The Purple Rain star passed away at his Paisley Park studios in Chanhassen on 21 April (16), and although an autopsy performed on Friday (22Apr16) failed to throw up an immediate cause of death, new reports suggest the superstar may have been battling an issue with painkillers he was taking for an ongoing hip injury in the days before his passing.

Federal law enforcement officials told NBC News on Wednesday (27Apr16) that the county sheriff has asked for assistance from DEA bosses, after prescription painkillers were found in his possession when he died.

The DEA will help determine where the medications were obtained and what prescriptions he had, both common checks performed by the government officials in death investigations.

Authorities have yet to say what role, if any, the medication may have played in his death.

Prince's remains were cremated on Saturday (23Apr16), shortly before the 57-year-old was remembered in a private service at Paisley Park, attended by his family and close friends, including ex-fiancee Sheila E, bass player Larry Graham, and his ex-wife Mayte Garcia.