The family of the late US musician Prince is suing his doctor over claims he failed to treat him for an opioid addiction.
The family's lawsuit alleges that failures by Dr Michael Schulenberg played a "substantial part" in the star's death.
Prince died from an accidental overdose of fentanyl, a powerful opioid, in April 2016.
Dr Schulenberg has denied any wrong doing, although he paid $30,000 to settle a federal civil violation alleging that he prescribed a drug illegally.
But the family's lawsuit filed in Hennepin County District Court this week alleges that Schulenberg and others had "an opportunity and duty during the weeks before Prince's death to diagnose and treat Prince's opioid addiction, and to prevent his death. They failed to do so."
According to the complaint, first reported by ABC News, the family of the singer - whose real name was Prince Rogers Nelson - is seeking unspecified damages in excess of $50,000 (£39,000).
A week before he died, the 57-year-old lost consciousness on a flight home from a concert in Atlanta.
The plane made an emergency stop in Moline, Illinois, where he was revived at Trinity Medical Center with a drug that reverses opioid overdoses.
John Goetz, a lawyer for Prince's six surviving siblings, said that the new lawsuit will eventually replace a lawsuit they filed in April in Illinois to beat a legal deadline.
"Prince lived in Minnesota all his life and passed away here, so we always thought his family's lawsuit belonged in Minnesota," Mr Goetz said.
He believes they now have sufficient legal grounds to pursue the lawsuit in Prince's home state. Paul Peterson, Dr Schulenberg's legal representative, has dismissed the lawsuit as meritless.
"We understand this situation has been difficult on everyone close to Mr Nelson and his fans across the globe," he said in a statement.
"Be that as it may, Dr Schulenberg stands behind the care that Mr Nelson received. We intend to defend this case."
Prince was found unresponsive in a lift at his Paisley Park Studios, Minnesota, on April 21 2016.
An investigation revealed he had experienced significant pain for a number of years and hundreds of different types of painkillers were found at his home.
Following a two-year investigation, Prosecutors said there was no evidence that the pills that killed Prince had been prescribed by a doctor and no evidence of intentional wrongdoing.
The new lawsuit by Prince's family also names North Memorial Health Care, where Dr Schulenberg worked at the time; UnityPoint Health, which operates the Moline hospital; and Walgreens, which operates two drug stores where Prince got prescriptions filled. The earlier lawsuit named only UnityPoint and Walgreens.
North Memorial said in a statement that it also stands behind the care Prince received. A spokeswoman for UnityPoint said they cannot comment on pending litigation.
"The Minnesota lawsuit is against all parties whom we now believe share legal responsibility for Prince's death, but it is possible that we will identify and add other parties as we move forward with the case," Mr Goetz said.