The singer was reportedly planning on getting treatment for an opioid addiction.
Prior to his death, Prince reportedly had plans to meet with a California doctor about an addiction to painkillers.
Minneapolis newspaper Star Tribune reports that William Mauzy says the singer's reps called Dr. Howard Kornfeld -- who runs Recovery Without Walls in Mill Valley, California, and deals with opioid addiction treatments -- on April 20 and scheduled him to speak with Prince, explaining that the singer was "dealing with a grave medical emergency."
Howard agreed to fly out and meet with Prince on April 22, but Mauzy, who is a prominent Minneapolis attorney working with the Kornfeld family, says the reps were adamant that they needed someone to speak with Prince immediately. The doctor then flew his son, Andrew Kornfeld, to the Paisley Park compound in Chanhassen, Minnesota, to go over how the confidential treatment program would work. "The plan was to quickly evaluate his health and devise a treatment plan," Mauzy says. "The doctor was planning on a lifesaving mission.”
According to the lawyer, Andrew was expected to meet with Prince the morning of April 21 after taking a red-eye flight from San Fransisco, California, to the compound. However, when he arrived to Paisley Park at 9:30 a.m., the 57-year-old musician was nowhere to be found. Andrew was the one who called 911 when Prince's body was found in the elevator a few minutes later. Mauzy says Andrew told him that the two other people at the compound at the time "were in too much shock" to make the call. Emergency responders arrived not long after, and Prince was pronounced dead at 10:07 a.m.
WATCH: Prince Used Percocet to Treat Persistent Pain From Hip and Ankle Injuries Starting in 2006
Andrew had a small amount of the narcotic buprenorphine to give Prince upon meeting him, but it was never administered, Mauzy says. The goal of him coming there was to get the singer to agree to long-term care under Andrew’s father's supervision, and have round-the-clock nursing support.
According to the Recovery Without Walls' website, the facility is a "personalized outpatient clinic, specializing in innovative, evidence-based medical treatment for chronic pain and drug and alcohol addiction."
WATCH: Sheila E. 'Concerned' Prince's Death 'Will Result in Exploitation for Profit'
ET has reached out to Mauzy for more on this account.
Last week, a law enforcement source told CBS News that prescription drugs were found in Prince’s possession and at his home at the time of his death. The source also said that the local sheriff's department has contacted the DEA about assisting with the investigation into the singer's death.
A week prior to his death, Prince's plane was forced to make an emergency landing in Moline, Illinois, where he was transported to a nearby hospital.
A source very close to the situation told ET that Prince was battling the flu, which turned into walking pneumonia. The "Purple Rain" singer was also dealing with a hip injury and had a problem with Percocet, according to the source. We are told his issue with the powerful narcotic began years ago, shortly after he underwent hip replacement surgery in 2010.