FILE - In this Nov. 22, 2015 file photo, Prince presents the award for favorite album - soul/R&B; at the American Music Awards in Los Angeles. ABC, NBC, CBS, and CNN, citing unidentified law enforcement... (Associated Press) 
 
 FILE - In this Nov. 22, 2015 file photo, Prince presents the award for favorite album - soul/R&B; at the American Music Awards in Los Angeles. ABC, NBC, CBS, and CNN, citing unidentified law enforcement... (Associated Press) 
 
 MINNEAPOLIS (AP) — Investigators are looking into whether Prince died from an overdose and whether a doctor was prescribing him drugs in the weeks before he was found dead at his home in suburban Minneapolis, a law enforcement official told The Associated Press on Thursday. 
 
 The official said that among the things investigators are looking at is whether a doctor was on a plane that made an emergency landing in Illinois less than a week before Prince died. 
 
 The law enforcement official has been briefed on the investigation and spoke to the AP on condition of anonymity because he was not authorized to speak to the media. 
 
 The official said investigators are also looking into what kind of drugs were on the plane and at Prince's house in suburban Minneapolis. 
 
 The official also confirmed some details that have previously been reported by other media outlets, including TMZ. 
 
 Prince's plane made an emergency stop in Moline, in western Illinois, on April 15 and he was found unconscious on the plane, the official said. The person said first responders gave Prince a shot of Narcan, which is used in suspected opioid overdoses. The official said the so-called save shot was given to when the plane was on the tarmac in Moline as Prince returned to Minneapolis following a performance in Atlanta. 
 
 The official said investigators are looking at whether Prince overdosed on the plane and whether an overdose killed him, and at what kind of drugs were involved. One possibility is the powerful painkiller Percocet or something similar, the official said. 
 
 Narcan can be used on people even if an overdose isn't confirmed because it wouldn't necessarily be harmful. 
 
 While it's premature to say where the investigation is heading, the mention of a doctor calls to mind other celebrity deaths, including Michael Jackson's. Jackson's doctor, Conrad Murray, was convicted of involuntary manslaughter for his role in prescribing a powerful anesthetic that contributed to the pop star's death in 2009. 
 
 A second law enforcement official told AP that prescription drugs were discovered at Prince's home when the musician was found dead on April 21. 
 
 That official spoke on condition of anonymity because the person was not authorized to speak about the ongoing investigation into Prince's death. The official did not elaborate. An autopsy has been performed, but results aren't expected for three to four weeks. The search warrant for Prince's Paisley Park home and studio — carried out the day of his death — was filed Thursday under seal at the request of investigators who said it would hamper their investigation if contents were public. 
 
 An affidavit in support of sealing the warrant, signed by Carver County Chief Deputy Jason Kamerud, also warned that disclosing details in the warrant could cause "the search or related searches to be unsuccessful" and risk injury to innocent people. 
 
 Kamerud declined to comment Thursday on the reports of drugs found at Paisley Park, and told AP that he strongly disputed reports by several media outlets that investigators had asked the U.S. Drug Enforcement Administration for help in the case. 
 
 "We have not asked them for help, or asked them to be a part of the investigation," Kamerud said. "We might contact them to help us, but that hasn't happened. We don't have the medical examiner's report yet. We don't know to what extent pharmaceuticals could be a part of this." 
 
 Leo Hawkins, a DEA spokesman in Chicago, said he had no comment. 
 
 Prince's death came two weeks after he canceled concerts in Atlanta, saying he wasn't feeling well. He played a pair of makeup shows April 14 in that city. Prince was scheduled to perform two shows in St. Louis but canceled them shortly before his death due to health concerns. 
 
 Longtime friend and collaborator Sheila E. has told the AP that Prince had physical issues from performing, citing hip and knee problems that she said came from years of jumping off risers and stage speakers in heels. 
 
 ___ 
 
 Tarm reported from Chicago. Tucker reported from Washington, D.C. ||||| Video (02:04) : The Twin Cities erupted in memories, grief and song after the passing of Minnesota's brightest star. 
 
 The investigation of Prince’s death took a turn Thursday indicating that the megastar’s collapse on April 21 is now the focus of a criminal probe. 
 
 In a three-page incident report, the Carver County Sheriff’s Office cited an exception to Minnesota public-records laws that allows it to suppress information relating to a “criminal” probe in deciding to release only scant information about the 911 response to the Paisley Park complex in Chanhassen that morning. 
 
 The law says that “investigative data collected or created by a law enforcement agency in order to prepare a case against a person, whether known or unknown, for the commission of a crime or other offense for which the agency has primary investigative responsibility are confidential or protected nonpublic while the investigation is active.” 
 
 The exception citation doesn’t mean that criminal charges will be filed at the completion of the Sheriff’s Office inquiry, only that charges are a possibility. 
 
 Sources with direct knowledge of the case have told the Star Tribune that they are investigating whether an overdose of opioids led to Prince’s death. Prescription pills were found at Paisley Park, but sources have said it was unclear whether they were prescribed to Prince. As part of the probe, investigators also are trying to determine how Prince got the pills, and who may have provided them. 
 
 Authorities have said that Prince was alone when he died and that neither foul play nor suicide is suspected. 
 
 Fans braved the rain and 40-degree temperatures Thursday to visit the Prince memorial at Paisley Park in Chanhassen. 
 
 Carver County Chief Deputy Jason Kamerud, who released the report, said Thursday that the federal Drug Enforcement Administration is not involved in the investigation at this time. Sheriff Jim Olson and County Attorney Mark Metz didn’t respond for comment. 
 
 The incident report, released a week after the musician’s death, provides little detail that wasn’t already made public by law enforcement authorities. It doesn’t identify who made the 911 call or if anybody in the building talked to investigators after Prince’s death. 
 
 Timeline of the 911 call 
 
 The report did reveal the time frame for the emergency response to Paisley Park that morning. Twenty-four minutes elapsed between the 911 call reporting an “unresponsive adult male” at Paisley Park and Prince being pronounced dead, according to the report. 
 
 The 911 call from the music studio was made at 9:43 a.m. Sheriff’s deputies and emergency personnel from the Chanhassen Fire Department arrived at the scene five minutes later and found Prince in the elevator. 
 
 Emergency responders administered CPR, but were not able to revive the rock star and he was pronounced dead at 10:07 a.m., the report said. 
 
 The cause of death was listed as “unknown.” 
 
 Prince was 57. 
 
 His body was cremated last week and a private service held at Paisley Park. 
 
 Olson has said a cause of death probably won’t become public for weeks, after the Sheriff’s Office receives reports from the medical examiner and toxicology results. 
 
 The Sheriff’s Office released the incident report at the request of media organizations. It also released, upon request, a list of 47 service calls to Paisley Park over the past five years. Four were for medical reasons. 
 
 Three of those medical calls occurred within the last nine months, including the final call. It is unclear whether medical calls on Aug. 9, 2015, and Sept. 6, 2015, involved Prince. 
 
 Search warrant sealed 
 
 Earlier Thursday, a Carver County judge sealed the search warrant in the death investigation. 
 
 The request was made by Metz, who stated that the premature disclosure of the details contained in the warrant may compromise the law enforcement investigation by causing the search or related searches to be unsuccessful. 
 
 He added that the release of the information could also create a substantial risk of injury to an innocent person or persons or severely hamper the ongoing investigation. 
 
 Search warrants in the investigation of Prince's death at Paisley Park in Chanhassen have been sealed by a Carver County judge at the request of the county attorney. 
 
 “Due to Prince’s status of having been an iconic popular music superstar, there is and will be continued intense media scrutiny upon the manner and circumstances of Prince’s death,” Metz said in his argument to seal the warrant and any related documents. 
 
 District Judge Eric Braaten ordered that the document remain sealed until the commencement of any criminal proceedings or 180 days from the date of Thursday’s order. 
 
 A search warrant is filed and made public no later than 10 days after its execution. The document typically provides a detailed narrative explaining why a law enforcement agency is seeking the warrant and lists the items or data seized during the search. 
 
 Staff writers Dan Browning, Emma Nelson and Jeremy Olson contributed to this report. ||||| (Reuters) - Authorities in Minnesota obtained a search warrant in connection with the death of pop star Prince and also won a court order to keep the findings secret, documents showed Thursday. 
 
 Chief Deputy Jason Kamerud of the Carver County, Minnesota, sheriff's office cited intense media scrutiny surrounding the death of the 57-year-old performer, in his request for a state district court judge to seal the warrant. 
 
 Prince, whose full name was Prince Rogers Nelson, died at his home, a compound known as Paisley Park, in suburban Minneapolis on April 21. Authorities investigating the death found prescription opioid medication on him, according to news outlets on Wednesday including CNN, the Minneapolis Star Tribune and others that cited anonymous law enforcement sources. 
 
 According to documents released by Kamerud on Thursday, the search warrant was for the Paisley Park compound, where Prince also had a recording studio. In an email to Reuters, Kamerud said the search had been conducted on April 21, the day Prince's body was found. 
 
 In a court order dated Thursday, state District Court Judge Eric Braaten approved sealing the results of the search for 180 days or until the beginning of court proceedings, whichever comes first. 
 
 Also on Wednesday, court records showed that a judge appointed a bank to safeguard Prince's estate.
– Investigators suspect an overdose of prescription drugs caused Prince's death last week and they want to find out exactly where he got them, according to a source close to the investigation. The probe is looking at whether a doctor was on Prince's plane when he made an emergency landing in Illinois the week before his death, and whether he overdosed on the plane, a law enforcement official tells the AP, which notes that the development is worryingly reminiscent of Michael Jackson's death. The source confirmed reports that the opiate painkiller Percocet is believed to have been involved. Documents released on Thursday signal that the investigation is now a criminal probe and charges are a possibility, the Star Tribune reports. The documents released by the Carver County, Minn., sheriff's office Thursday include a request to seal the results of a search conducted at Prince's Paisley Park the day he died, Reuters reports. A judge granted the request, which was made on the grounds that "intense media scrutiny" could hamper the investigation or risk injury to innocent people. Carver County Chief Deputy Jason Kamerud declined to comment on reports of drugs found at Prince's home. He tells the AP that contrary to media reports, investigators have not asked the DEA to get involved. "We might contact them to help us, but that hasn't happened," he says. "We don't have the medical examiner's report yet. We don't know to what extent pharmaceuticals could be a part of this." (Prince was given a private send-off last weekend.)