The family of the late rock star Prince is suing a doctor who prescribed pain pills for him, saying the doctor failed to treat him for opiate addiction and therefore bears responsibility for his death two years ago from an accidental overdose of fentanyl.

Authorities say Dr Michael Schulenberg admitted prescribing a different opioid to Prince in the days before he died, oxycodone, under his bodyguard's name to protect the musician's privacy.

Prince's family seeks unspecified damages in excess of US$50,000. An attorney for his six surviving siblings said the lawsuit would eventually replace one filed in April to beat a legal deadline.