Danish police say the freelance Swedish journalist Kim Wall died aboard the do-it-yourself UC3 Nautilus submarine captained by inventor Peter Madsen, who had initially claimed to have dropped her off at the tip of a Copenhagen island. After over a week of denying any role in Wall's disappearance, on Monday he admitted to dumping her body into the ocean. 
 
 Madsen "told police and the court that there was an accident on board the sub that led to the death of Kim Wall, and that he subsequently buried her at sea in an undefined location of the Koge Bay," approximately 50 kilometers (30 miles) south of Copenhagen, officers reported in a statement. 
 
 Last week, Danish authorities upgraded an initial charge of involuntary negligent manslaughter against Madsen, who owned and designed the amateur-built submarine - the biggest homemade underwater boat ever when it first took to the seas in 2008. Danish police say Madsen deliberately sank the 18-meter (60-foot) submarine in the Bay of Koge, south of Copenhagen, shortly before his rescue on August 11. 
 
 Wall's family had feared the worst 
 
 The new charge of aggressive manslaughter covers deaths that occur in such instances as a killer's driving under the influence of alcohol or other drugs. In Denmark, the crime can lead to a sentence of up to eight years in prison. 
 
 Until Madsen confessed, police from Denmark and Sweden and members of the voluntary Swedish Lifesaving Society had conducted a search of the waters of the Oresund straits between the two countries and parts of their coastlines with dwindling hopes of finding her alive. At one point, chief investigator Jens Moeller Jensen acknowledged that "it is our clear presumption that we are looking for a dead person." 
 
 mkg/msh (AFP, dpa, AP) ||||| “The accused has told police and the court that an accident occurred on board the submarine which caused Kim Wall’s death, and that he subsequently buried her at sea at an unspecified location somewhere in Køge Bay. Copenhagen Police can additionally confirm that the current charges remain in place. No further information will be given with regard to the investigation of the case, since it is being conducted behind closed doors,” the police statement read. 
 
 The information was approved for release by Copenhagen City Court following a request from the prosecution authority, according to the police statement. 
 
 Both Swedish and Danish marine authorities have now mapped out a detailed track of the route taken by the submarine in the Öresund Strait and Køge Bay on the evening of Thursday August 10th, when Madsen’s NC3 Nautilus submarine disappeared, through to it being relocated at 10:14am the following day, police also confirmed. 
 
 The search for Wall’s body by both Danish and Swedish authorities is continuing on Monday. 
 
 Divers from the Danish side of the investigation began on Friday searching along the route mapped by the investigation and will continue with this work today, according to the statement. 
 
 Investigation over the weekend has involved the use of sonar trackers as well as helicopters and boats. 
 
 Freelance journalist Wall vanished after having boarded the 18-metre UC3 Nautilus sub on the evening of August 10th, apparently as part of her work on a feature story about its owner, inventor and entrepreneur Peter Madsen. 
 
 Madsen was brought back alone to a harbour on Copenhagen on Friday after the vessel sank in waters near Køge Bay. 
 
 The submarine owner claimed prior to his arrest that he had been alone on the vessel overnight when it experienced the technical problems that eventually caused it to sink. 
 
 “I was just taking a practice trip, where I was playing with various things on the submarine, when a fault developed,” he told Danish media TV2 shortly after returning to land on Friday August 11th. 
 
 He initially claimed that he had brought Wall back to land at around 10:30pm on the night of her disappearance. 
 
 Broadcaster DR reported on Monday that Madsen told Copenhagen City Court nine days ago that Wall had died on board the Nautilus submarine. 
 
 Madsen provided the court with his explanation on August 12th, according to the report. 
 
 The information was kept behind closed doors by the court until today. 
 
 Madsen’s lawyer Betina Hald Engmark told DR that her client was “relieved” that his explanation had now been made public. 
 
 “That was his wish from the beginning,” Engmark said. 
 
 The lawyer was unable to confirm whether Wall’s family had already been informed of his explanation. 
 
 46-year-old Madsen was accused of causing Wall's death "in an unknown manner" before being remanded in custody for 24 days on August 12th on suspicion of manslaughter. 
 
 The Swede's body was not found inside the submarine after it was raised and brought to Copenhagen for forensic examination. 
 
 Last week, police stated that they would not release details of the evidence found on board the vessel, in order to avoid prejudicing the ongoing investigation. 
 
 But they confirmed on Friday that they did not expect to find Kim Wall alive. 
 
 READ ALSO: Kim Wall presumed dead: Copenhagen Police 
 
 
 
 Submarine disappearance timeline: What we know so far 
 
 Thursday August 10th 
 
 7pm: The submarine, crewed by its owner Peter Madsen and a Swedish journalist, sails from the Refshaleøen island harbour near Copenhagen. 
 
 8:30pm: Denmark military authorities receive a message from a cruise ship that observed the submarine sail out of Copenhagen Harbour, according to a DR report. 
 
 Around midnight: “Ferry traffic” sights Nautilus for the last time until the following morning. 
 
 Friday August 11th 
 
 2:30am: The partner of the Swedish woman reports that the craft is missing. Danish authorities begin searching for the submarine. 
 
 10:14am: The submarine is sighted in Køge Bay. Radio contact is made and the owner says he is setting course to Copenhagen, and that the submarine has technical problems. Nautlius sinks shortly afterwards. 
 
 11:00am: The owner is recovered by a private boat, but there is no sign of the second crew member. The owner is sailed to land at Dragør Harbour. 
 
 Afternoon: Police in Sweden state that a missing person alert issued during the morning pertains to the woman on board the submarine and remains in place, reports Swedish news agency TT. 
 
 5:44pm: Copenhagen police announce through a press statement that the owner of the Nautilus has been charged over the woman's death. Police divers have located the sunken submarine but have not yet gained access to it. 
 
 Saturday August 12th 
 
 Afternoon: Madsen is remanded in custody for 24 days by Copenhagen City Court as work to raise the submarine begins and the identity of the woman emerges as journalist Kim Wall, after her family contacts Danish media. 
 
 Sunday August 13th 
 
 The raised submarine is brought to land and police technicians begin their examination, but no body is found on board. 
 
 Monday August 14th 
 
 9:30am: Madsen's lawyer informs media that her client accepts his preliminary detainment on charges of manslaughter. 
 
 2:26pm: Following a forensic examination of the wreck, police announce that they believe the submarine to have been deliberately sunk. 
 
 1:53pm: Police announce that they are broadening their search area towards the Swedish coast, are working in cooperation with Swedish authorities and are using aircraft in the search for Wall. 
 
 Thursday August 17th 
 
 Police confirm that they are searching for a “dead person in the area around Køge Bay on both the Danish and Swedish sides”, and that aircraft searches have failed to yield any strong new leads in the search. 
 
 Friday August 18th 
 
 Kim Wall’s family appeal to the public and authorities to help them find closure in the case. 
 
 Monday August 21st 
 
 Madsen told the court that he buried Wall at sea somewhere in the Køge Bay area after she died following an accident on board the submarine, police confirm. ||||| Image copyright Ritzau Foto Image caption Kim Wall boarded Peter Madsen's submarine Nautilus on 10 August, and then disappeared 
 
 A Danish inventor charged over the death of Swedish journalist Kim Wall has said she died in an accident on his submarine and he "buried" her at sea, Copenhagen police say. 
 
 The court case is being heard behind closed doors but Peter Madsen's explanation of what happened was released after a request from the defence and prosecution. 
 
 Ms Wall was last seen on Mr Madsen's submarine on the night of 10 August. 
 
 The search for her body continues. 
 
 In a statement, Copenhagen police also said that maritime authorities had determined the route the submarine travelled in Koge Bay and the Oresund strait before sinking. 
 
 Mr Madsen, 46, claims that he left her body somewhere in Koge Bay, south of Copenhagen, the police said. A search effort involving divers, helicopters and ships has been under way along the identified route since Friday. 
 
 The Danish inventor has been charged with negligent manslaughter. The police say they cannot release any more information at this time. 
 
 Peter Madsen's lawyer, Betina Hald Engmark, said her client had not admitted any wrongdoing. She said he had given evidence to the police during preliminary questioning and "information from this" had now emerged. 
 
 "My client has not confessed to anything, my client still pleads not guilty to the charges against him," she said. 
 
 Image copyright Reuters Image caption Police believe Mr Madsen deliberately sank the submarine 
 
 Ms Wall, a 30-year-old journalist who wrote for several international publications, was first reported missing by her boyfriend after she failed to return from what should have been a short trip on the UC3 Nautilus submarine. 
 
 She had been researching a feature about Mr Madsen and his 40-tonne submarine, which at one stage was the largest privately-made vessel of its kind. 
 
 Police believe the submarine was deliberately sunk by Mr Madsen, who was rescued before being arrested. 
 
 Mr Madsen initially said he dropped Ms Wall off after dark on 10 August, close to where they had met earlier. But police later said he had given them a new account of events, which was not made public at the time.
– The mystery of what happened to a Swedish journalist who vanished after a ride on a Danish inventor's submarine is slowly becoming clearer. Though details are still scarce, Copenhagen police say Peter Madsen, after changing his story, has confessed that Kim Wall died in "an accident" on board his Nautilus sub and that he then "buried her at sea," the BBC reports. Officials have been searching for Wall since her disappearance on Aug. 10, when she boarded Madsen's sub, which then sank off of Denmark's Refshaleoen island. Madsen initially claimed he had dropped Wall off after they'd cruised around for about three hours, but in a police statement cited by the Local, that story has since been modified. "The accused has told police and the court that an accident occurred on board the submarine which caused Kim Wall’s death, and that he subsequently buried her at sea at an unspecified location somewhere in Koge Bay," reads the statement in the closed-door case. Madsen's explanation was released after a defense and prosecution request. Although the statement also notes that "current charges remain in place," it's unclear what those charges are: Deutsche Welle notes that Madsen was originally charged with negligent manslaughter, but it's now reporting a new charge of aggressive manslaughter, which it says can lead to a prison sentence of up to eight years. A search for Wall's body in the newly pinpointed area is now underway.