Private investigators believe that the billionaire Toronto couple found dead at their home in December were murdered by multiple killers, a source with direct knowledge of the parallel probe into their mysterious deaths told CBC Toronto. 
 
 The new information contradicts a widely circulated theory that Barry and Honey Sherman died as a result of a murder-suicide — a notion that is regarded as fiction by those who knew the Shermans well. 
 
 Barry, 75, and Honey, 70, were found dead by a real estate agent in the basement of their Toronto mansion on Dec. 15. The source said their bodies were in an upright seated position on the floor near an indoor pool. Police deemed the deaths "suspicious" but have said little else since their investigation began. 
 
 The Sherman family has hired a team of experts, which includes a number of former Toronto homicide detectives, to conduct a separate, independent investigation. 
 
 The private investigators have found evidence that both Barry and Honey Sherman had their necks wrapped with leather belts that were then knotted around a handrail that runs adjacent to the pool, the source told CBC Toronto. A coroner previously ruled that the couple had died from "ligature neck compression," or strangulation. 
 
 The Shermans' North York home is still blocked off by Toronto police. The couple's four children plan to have the house demolished after a team of private forensic experts can scour the premises. (James Morrison-Collalto/CBC) 
 
 Their wrists showed evidence that they had been, at one point, bound together. No rope or other materials that could have been used to tie their wrists were discovered, the source told CBC Toronto. 
 
 Their bodies were otherwise limp and their arms unbound when they were discovered, the source said. The day the Shermans were found police said that there was no evidence of forced entry into the home. 
 
 The team of private investigators believes that the Shermans were, in fact, killed on Dec. 13, two days before they were found. This conclusion is based on the fact that Honey was wearing the same clothes she was last seen in, on Dec. 13, according to the source. 
 
 Private investigators also believe that Honey struggled with her killer or killers. She had cuts on her lip and nose, and was sitting in a pool of her own blood when she was discovered. However, there was comparatively little blood apparent on her upper-body clothing, suggesting that she had been face-down on the tile, bleeding, for some time before being bound to the handrail in an upright position, the source said. 
 
 Neighbours continue to drop flowers outside the Shermans' home. The couple was highly visible in Toronto, often lending their names and fortune to charitable causes and also philanthropic work that extended beyond Canada. (James Morrison-Collalto/CBC) 
 
 Various media outlets have reported that Toronto homicide detectives are probing the deaths as a possible murder-suicide. The couple's four children, who plan to have their parents' North York home demolished once a team of private forensic investigators have had time to scour it, have soundly rejected that theory. So have close friends of the Shermans. 
 
 Barry Sherman is the founder of Canadian pharmaceutical giant Apotex, and both he and his wife have been recognized internationally for their generous philanthropy. The couple, who were quite socially active among the city's gala class, was believed to have amassed a fortune of some $4.77 billion before their deaths. 
 
 Neighbour Eli Kanter said he was unsurprised to hear that private investigators are approaching the case as a double murder. He told CBC Toronto that he's been skeptical about the possibility that the Shermans died in a murder-suicide since it was first reported as a possibility that the police are considering. 
 
 "They wouldn't do that. They wouldn't end that way," he said. 
 
 Contacted by telephone on Saturday morning, a Toronto police spokesperson said the force's own investigators have no updates at this time. ||||| Into its fourth day Monday, the probe into the demise of Barry Sherman, the 75-year-old founder of generic drug giant Apotex, and his wife, Honey, 70, has attracted worldwide attention and sent shockwaves across the country, including among the political and social elite. 
 
 The lights inside Barry and Honey Sherman’s multimillion-dollar home in a tony North York neighbourhood were beaming Monday night, two forensic vans and a Toronto police cruiser still parked outside as investigators continued their grim task of determining what, exactly, transpired in the final moments of one of Canada’s richest couples inside 50 Old Colony Rd. 
 
 That the deaths are suspicious is both an understatement and their official status. As of Monday night, neither death had been classified as a homicide, despite the involvement of Toronto police homicide detectives. The squad officially took the lead of the probe Sunday evening, though it had been involved in the case since the couple’s bodies were discovered before noon Friday. 
 
 “These causes of death can be seen in homicides and suicides and rarely accidents,” said Christopher Milroy, director of forensic pathology at the Ottawa Hospital, who is not involved in the Sherman investigation. 
 
 The pathological term means either death from hanging or strangulation with a ligature. Former homicide investigators told the Star on Monday that marks on the neck can allow pathologists to make the distinction between manual strangulation and the use of a cord of some kind, like a rope. 
 
 While little information has formally been released by police, the details that have come out are beginning to provide some insight into the mysterious deaths — starting with its cause. Autopsy results released late Sunday reveal both Barry and Honey Sherman died from “ligature neck compression.” 
 
 Speaking late Friday night to “alleviate concerns in the neighbourhood,” a Toronto police detective said they were not seeking a suspect. A police spokesperson said Monday that no further information could be provided than what was contained in a brief public release Sunday, which did not contain any information about police seeking a suspect. 
 
 “Hanging is normally a suicide. Ligature strangulation is most commonly seen in homicides, but may be seen in other manners of death,” he said. 
 
 A police source told the Star the couple were discovered by their real estate agent and found near their indoor lap pool, photos of which were recently included in a real estate listing for the home, valued at $6.9 million. Multiple news outlets have reported that the couple were found hanging; the Star has not independently confirmed this. 
 
 The Star and other news outlets, citing police sources, have reported an early theory for investigators had been that the deaths may have been a murder-suicide. 
 
 The Sherman family released a statement Saturday calling that theory a rumour, saying it was “irresponsible that police sources have reportedly advised the media of a theory which neither their family, their friends nor their colleagues believe to be true.” 
 
 Other possibilities are that the deaths are a double-homicide or suicides, said former police officers consulted by the Star on Monday. The exact circumstances of death may also end up undetermined. 
 
 The specialized team now conducting the probe is amassing the critical bits of information gathered from both the crime scene and the autopsy. In all suspicious death autopsies, investigators seek other clues that may be on the body, including signs of struggle. That could include skin cells of another person under the nails, scratches, unusual bruising — in this case, anything over and above the ligature neck compression. 
 
 Stomach contents, too, may provide clues in suspicious death cases, including insight into whether any drugs had been ingested, said Mark Mendelson, a former Toronto police homicide investigator who is now a security consultant. 
 
 Investigators are also awaiting the results of toxicological reports, including blood and urine samples, which would provide more information including about drugs, Mendelson said. These test results can take weeks or more, he said. 
 
 He added that the homicide unit’s taking the lead in the case may simply mean that investigators who are “most experienced in dealing with sudden unexpected deaths” were needed. 
 
 “They’re the experts, and that’s why it’s gone to them. If it was a homicide, they would be calling it one. But the investigation is still going on,” he said. 
 
 Meanwhile, police and forensics experts still at the scene are probably wrapping up their probe, the experts said. That includes a review of any available surveillance video either inside the Sherman residence, outside, or in the area; one neighbour told the Star that police had been by asking for security camera footage. They are also probably conducting a forensic analysis of the Shermans’ phones. 
 
 “The crime scene will tell the story,” said Dave Perry, a former Toronto police homicide detective who is now the CEO of Investigative Solutions Network, speaking generally about death investigations. 
 
 “One thing that I learned in all my years of working in violent crime and homicide is that, forensically, it’s still quite amazing what we can learn at a crime scene,” he said. “It’s some very old school techniques — footwear impressions, lighting up the place for any kind of forensic evidence or bodily fluids, finger prints and smears, and manner and mechanisms of the death.” 
 
 Perry added that it is telling when deaths are not immediately deemed homicides and where suspects are not being sought and police say there is no public safety risk. ||||| Less than a week before the billionaire businessman Barry Sherman and his wife, Honey, were found dead in their Toronto mansion, Ms. Sherman was cheerfully making plans for the couple's annual trip south. 
 
 "Looking forward to getting together in Florida. I am coming south Monday, December 18 [to]Friday, January 12," she wrote in an e-mail to friends last Monday. 
 
 What happened to Barry and Honey Sherman? What we know so far about the Apotex founder's death 
 
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 "Barry is coming south for Monday December 25 & going home with me Jan. 12. Please let me know your dates south asap so i can place in my calendar … Looking forward to hearing back asap. Xoxo Honey." 
 
 Instead of looking forward to socializing with Ms. Sherman on what was to be the first day of her vacation, friends of the couple are reeling – stunned that the pair were found hanging from a railing partly surrounding their basement lap pool on Friday. 
 
 Late Sunday, Toronto police said the couple both died from "ligature neck compression." 
 
 The homicide squad is now in charge of the investigation, although police were still classifying the deaths as "suspicious," not a homicide, in their Sunday night statement. 
 
 Over the weekend, multiple media reports and a Toronto police source said the early theory of investigators was that Mr. Sherman may have killed his wife and then took his own life. 
 
 However, the couple's grown children dismissed outright the suggestion that a murder-suicide was behind the deaths. 
 
 "Our parents shared an enthusiasm for life and commitment to their family and community totally inconsistent with the rumours regrettably circulated in the media as to the circumstances surrounding their deaths," the family said in a statement released Saturday evening. 
 
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 "We are shocked and think it's irresponsible that police sources have reportedly advised the media of a theory which neither their family, their friends nor their colleagues believe to be true." 
 
 The couple had four children and had recently welcomed a new grandchild. 
 
 Toronto police did not officially confirm until late Sunday that the bodies discovered at 50 Old Colony Rd. in the city's north end on Friday were those of Mr. Sherman, 75, the founder of generic pharmaceuticals giant Apotex Inc., and his 70-year-old wife, Honey, a gregarious philanthropist whose causes ranged from higher education to health care to the Jewish community. 
 
 A Toronto police source told The Globe and Mail that a real estate agent who had been helping to sell the Shermans' North York home – it was recently listed for $6.9-million – discovered the bodies on Friday morning. 
 
 There was no sign of forced entry to the home and no note left behind to explain what had happened, the police source said. 
 
 As tributes and condolences poured in over the weekend – including from Prime Minister Justin Trudeau and Toronto Mayor John Tory – friends of the Shermans in Toronto's tight-knit Jewish community struggled to find an explanation for their deaths. 
 
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 "It was like being hit with a bolt of lightning on Friday," said Paul Godfrey, the chief executive officer of Postmedia Network Inc., who has known the Shermans socially for more than 25 years. "Everybody is asking, 'How could this happen?'" 
 
 Honey and Barry Sherman were proof that opposites attract, according to people who knew the couple. 
 
 Ms. Sherman was warm, genuine and loved to socialize. Mr. Sherman was a renowned workaholic, not comfortable with small talk and occasionally let on that he would rather go to the dentist than attend another fundraiser. But he always showed up because it was important to his wife. 
 
 Mr. Sherman talked business with a handful of friends at a reception in Toronto a few weeks ago for federal Conservative Leader Andrew Scheer, a party hosted by Senator Linda Frum. 
 
 At that party, Mr. Sherman made it clear that he still loved what he was doing and had no plans to leave Apotex, according to a Bay Street executive who knew the couple well. 
 
 Mr. Sherman gave no hint there were any financial problems at Apotex, the executive said. 
 
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 The couple were planning a dinner party with a number of Toronto friends at their winter home in Palm Beach later this month; informal invitations went out last week, asking when a number of couples were free. 
 
 Mr. Sherman's net worth was recently estimated to be $4.77-billion by Canadian Business, an online magazine, making him the 15th-richest person in Canada. 
 
 The Shermans have handed out millions of dollars to hospitals, universities and the United Jewish Appeal. Ms. Sherman was on the board of governors at York University, the Baycrest Foundation and Mount Sinai Hospital. She was also the past chair of the Jewish Foundation of Greater Toronto and former chair of the Holocaust Education Centre. 
 
 Rhonda Lenton, the president of York University, last saw the Shermans on Oct. 28 after a concert by the Israel Philharmonic Orchestra at Toronto's Roy Thomson Hall. 
 
 The couple were in a buoyant mood that night, Dr. Lenton recalled, especially the more outgoing Ms. Sherman. 
 
 "[Ms. Sherman was] warm and effusive and bubbly," she said. "Because she is involved in so many different boards and quite involved in the Jewish community, she's known by everybody. She loves chatting." 
 
 Friends and colleagues have long said that Mr. Sherman was consumed with work and that he devoted almost all of his time and energy to Apotex, frequently sleeping for only a few hours a night. He had almost no outside interests and no taste for luxury, once driving an old car into such disrepair that Ms. Sherman went out and bought him a new Mercedes. 
 
 "Barry liked to do one thing: work. He worked seven days a week and he loved it," said Murray Rubin, 87, a retired pharmaceutical-industry colleague. 
 
 Mr. Rubin described the couple as kind and generous, and says he was shocked by the news of their deaths, and expressed disbelief that it could have been a murder-suicide. 
 
 "That is impossible," he said on Saturday. 
 
 With reports from Tu Thanh Ha, Joe Friesen, Molly Hayes, Tavia Grant, Jeff Gray and Susan Krashinsky Robertson
– The investigation into the mysterious deaths of a billionaire and his wife is now being led by homicide detectives, police say—suggesting the deaths of Barry and Honey Sherman were either murder-suicide or a double murder. Police, who have described the deaths as "suspicious," revealed Sunday that the cause of death for both Shermans was "ligature neck compression," a form of strangulation, the CBC reports. Sources have told the media that the couple were found hanging near an indoor pool in the basement of their Toronto mansion. Police say they haven't found any sign of forced entry, or a note that could explain what happened to 75-year-old pharmaceutical tycoon Barry Sherman and his 70-year-old wife, both renowned philanthropists. The couple's four children have rejected what they say are "rumors" that the deaths are being investigated as a murder-suicide, and many of the influential couple's friends agree. "There is absolutely zero debate in my mind, this was a double homicide," says Canadian Sen. Linda Frum, a longtime friend of the couple, per the New York Times. The Globe and Mail reports that just days before the bodies were found, Honey Sherman was enthusiastically making plans for their annual trip to Florida, emailing friends that she would be traveling to the state on Dec. 18 and Barry Sherman would join her a week later. The couple also sent out invitations last week to a dinner party at their winter home in Palm Beach.