Police investigating the death of music icon Prince have said that he may have died as a result of a "fatal mix of drugs," it has been reported. The 57-year-old was found unresponsive in the lift at his Paisley Park home on 21 April.

The investigation has focused on the singer's alleged addiction to prescription painkillers after he was found to have powerful opioids on his person at the time of death. While toxicology reports are still pending, investigators are considering the possibility that the Purple Rain singer may have ingested a lethal combination of drugs. According to TMZ, Prince may have had both Percocet and Buprenorphine in his system, which if combined, increases the effect of each drug on the body as well as inhibiting breathing.

The latest development in the enquiry comes as it was revealed that Dr Andrew Kornfield, who attended to Prince at the scene, had Buprenorphine pills in his backpack, Mail Online reports. The son of addiction specialist Dr Howard Kornfeld, he was reportedly at the Paisley Park compound to explain to the singer the details of the rehabilitation programme at his father's California practice, Recovery Without Walls. Prince's team reportedly contacted Dr Howard Kornfeld following growing concerns that the singer's alleged addiction to painkillers had spiralled out of control.

Andrew Kornfeld's lawyer claims that he was merely transporting the drug which is used to treat opiod addiction, which were to be given to Prince's personal physician Dr Michael Schulenberg and had not administered them to the singer.

Police are also investigating Dr Schulenberg who had told police he had written prescriptions for Prince who was seen just a day before his death visiting Walgreens pharmacy. It was earlier reported that the Grammy award winning artist may have been using aliases to obtain prescriptions. On 11 May, Federal authorities obtained a warrant to search the singer's home. On the same day, Dr Schulenberg is reported to have left his practice in Minnetonka, Minnesota.

While Prince's legal team have been eager to assert that the musician had a healthy lifestyle, friends of the star have described the Purple Rain star's growing dependency on prescription painkillers following corrective hip surgery in 2010. Sky Dangcil who performed with Prince, claims he was often in pain while on stage and relied on the pills to "keep the show going". "He was always 'on,' so he wouldn't complain or say anything was wrong," explained Dangcil.

While the Midwest Medical Examiner's Office in Ramsey, Minnesota, has ruled out suicide as a possible cause of death, an official ruling is yet to be made. The investigation is continuing as police attempt to determine whether criminal conduct may have been a factor in Prince's tragic death.