Days after Prince's death from a fatal dose of fentanyl, his longtime friend and closest associate told police that he didn't know the musician was addicted to painkillers until a week before he died.

But records made public this week after authorities closed the death investigation without criminal charges showed that several others close to the megastar worried about his use of painkillers for years, well before he had hip replacement surgery in 2010 and a brush with death in Moline, Ill., a week before his accidental overdose.

Federal, state and county law enforcement officers spent almost two years interviewing Prince's associates, employees, family members and medical personnel while trying to trace the source of the fentanyl that killed him. They got nowhere. Pieced together, however, their legwork reveals a superstar who thought his privacy would protect him but, in the end, kept help at bay.

Kirk Johnson, Prince's security and property manager, told law enforcement officers that he only learned that Prince was addicted to opioids shortly before he died on April 21, 2016.

Josh Welton, who played in Prince's band and was his recording engineer, let detectives know that doing drugs wasn't "part of our core values."

"We didn't like the drug ­environment. It's nothing that we were around," Welton said. "That was something he prohibited."

Several other former employees said they saw no evidence that Prince was addicted to painkillers.

But others told investigators that Prince had been taking pain pills for years.

Lawyer Michael Padden told authorities shortly after Prince's death that former clients Lorna Nelson and Duane Nelson had expressed concern long ago about Prince's use of Percocet and cocaine. Lorna Nelson, a half-sister of Prince, died in 2006. Duane, who died in 2011, is believed to be no relation to Prince, although they were raised as brothers.

Manuela Testolini, who was married to Prince from 2001 to 2006, told investigators that he "was using narcotic pain pills during their marriage to manage pain."

Crystal Zehetner, Prince's personal chef and business manager from 2010 to 2012, said he would often complain about hip pain and "everyone knew Prince was addicted to pain pills." Anyone who worked closely with him who said otherwise was "lying," she told one officer.

Zehetner said she told incoming business manager Phaedra Ellis-Lamkins that one of the reasons she had quit in 2012 was because she did not want to be a "drug dealer." Zehetner clarified that statement by saying Prince never asked her directly to get him pain pills.

"Crystal said Prince was able to get his pills from doctors he would have Crystal and other assistants set up for him," according to investigative records. "Crystal told me that she could not watch Prince and his drug addiction so that is why she left, only working consulting jobs after that."

Musician Sheila Escovedo, known by her stage name Sheila E., told investigators that it was obvious that Prince was in a lot of pain before his hip surgery at the Mayo Clinic in Rochester in 2010. He could barely walk, she said, but didn't want anyone to know how much pain he was in. She said he took pain pills but had no idea where he got them. She said back in the day, Prince's staff would get prescription pain pills for him in their own names.

Richard Lee Peloquin, a groundskeeper at Prince's Paisley Park recording studios in Chanhassen, where Prince's body was found, told investigators that Prince was prescribed Percocet after the hip replacement surgery but he had a reaction and was running around Paisley Park naked, complaining he was hot.

Peloquin told authorities that he contacted Prince's chiropractor about Prince's odd behavior and was told it was likely a reaction to "the Percocet leaving Prince's system." Peloquin said he had heard rumors about Prince being addicted to pain pills but that was the only incident he had witnessed.

Kiran Sharma, Prince's manager from 2008 to 2014, told investigators that she helped with public relations after Prince died. Sharma said Ellis-Lamkins showed her a number of text messages she'd received from Johnson and Prince's personal assistant, Meron Bekure, regarding Prince and his drug use shortly before his death. She said Ellis-Lamkins' sister had been treated for drug addiction by Dr. Howard Kornfeld through his California clinic, Recovery Without Walls. Sharma said Ellis-Lamkins arranged for Prince to be treated by Kornfeld.

Ellis-Lamkins clarified in an e-mail Saturday that her sister had never heard of Kornfeld until after Prince had died, and in fact, had never been treated by him. She said in the e-mail that "Howard Kornfeld was referred to me, the day before Prince died, from the Director of a Residential Rehab program."

Bekure made brief comments to investigators after Prince's death but declined their requests for interviews later, according to court records. Ryan Garry, Bekure's attorney, said Friday that she is glad the investigation has closed and looks forward to moving on.

"It's been a tough couple of years emotionally, and the county attorney's decision not to prosecute has confirmed our position from the very beginning," Garry said.

Ellis-Lamkins also declined investigators' requests for an interview. Kornfeld said through his attorney, Bill Mauzy, that he couldn't see Prince immediately when the musician's staff reached out for help, so he sent his son, Andrew, on a red-eye flight from San Francisco to Minneapolis. Andrew Kornfeld arrived at Paisley Park just after Prince died. He told authorities that he inferred from discussions with Prince's staff that he had a drug problem. "They said the issue was with prescriptions, not street drugs," he said. He told investigators Johnson had told him "Prince was struggling with some opiates."

F. Clayton Tyler, Johnson's attorney, said Friday that his client had nothing to do with Prince's death, and "I don't need to defend him."

The forensic investigation was equally fruitless in tracking the fentanyl source.

In March 2017, investigators sent 64.5 counterfeit Vicodin pills Prince stored in a Bayer aspirin bottle to the DEA's Chicago lab for testing. The DEA wanted to see if the illicit pills matched samples seized elsewhere around the country.

Kenneth Solek, assistant special agent in charge of the DEA's Twin Cities division, said Friday that the DEA looked for clues like binding and coloring agents or unique marks left behind by pill presses. DEA scientists also tried to find chemical impurities to see if they matched the "signature" of other seized pills, Solek said.

According to Carver County investigative records, a DEA investigator reported that Prince's death was the only one traced by the agency to a fentanyl pill in Minnesota in 2016. That year, fentanyl-related deaths in the state exceeded 100 for the first time, but investigators found most cases involved powdered fentanyl laced into other drugs like heroin or cocaine.

By July 2017, the DEA reported that it could not turn up any pills tested in its database with a similar composition to the ones found at Paisley Park. Authorities weren't surprised because "they are seeing these types of pills being mixed with whatever is around or whatever is easily available," a Carver County detective wrote.

Investigators had no other leads.

Staff writer Jeremy Olson contributed to this report. 612-673-4493 612-673-4465 612-673-1755