AceShowbiz - Prince's brothers and sisters are suing a doctor who prescribed the late music icon pain pills, insisting he's partly responsible for the star's death.

In a new lawsuit filed in Minnesota's Hennepin County District Court, the family members claim Dr. Michael Schulenberg failed to treat the "Purple Rain" star for opiate addiction.

Schulenberg previously disputed investigators' claims he prescribed oxycodone to Prince under his bodyguard's name to protect the singer's privacy, and now his attorney has shot down the family lawsuit, contending it has no merit.

The late star's kin claim the doctor is among several defendants who should have diagnosed Prince's opioid addiction in the weeks before his death and prevented it.

The lawsuit seeks unspecified damages in excess of $50,000 (GBP39,000), according to Billboard.

Prince was caught on surveillance cameras looking frail as he visited Dr. Schulenberg with his assistant, Kirk Johnson, on the day before he died. During the visit to the clinic, he reportedly told the medic he was feeling "antsy" and questioned whether he was suffering side effects as he had stopped taking painkiller Tylenol earlier that day.

Text messages between Johnson and Schulenberg on April 7, 2016(16) also show that the assistant was concerned for Prince's health and wanted him to see a doctor.

In an interview with investigators Johnson said he didn't realise Prince had an opioid addiction until he passed out on a plane a week before he died.

Prince was found unresponsive and slumped in an elevator at his Paisley Park compound near Minneapolis in April, 2016. Coroners ruled he died of an accidental overdose of fentanyl.

It has since come to light that the musician had been taking medication for years to ease the agony of a hip issue.