As authorities continue their investigations into the circumstances leading to Prince's untimely death, it has been reported that the singer's primary physician Dr Michael Schulenberg and renowned addiction specialist Dr Howard Kornfeld are both being investigated.

TMZ reports that police want to determine whether the medics wrote prescriptions for the singer or facilitated his acquisition of medication in the days before he was found dead at his Paisley Park home.

Prince died on 21 April 2016 following a self-administered overdose of the powerful painkiller, Fentanyl. According to the autopsy report, at the time of his death, the 5ft 3in singer weighed just 112lbs.

Schulenberg saw Prince on 7 April and 20 April and Kornfeld, a California addiction specialist, was also asked by Prince's representatives to help the singer the day before he died, according to a lawyer for the doctor.

In was revealed earlier in June that Kornfeld was carrying buprenorphine, a medication that can be used to treat opioid addiction. He claimed that he intended to give the medication to a Minnesota doctor who was seeing Prince the following day but has refused to name that doctor.

Schulenberg, who is not authorised to prescribe the drug buprenorphine, was at Prince's home when his body was discovered, but says he was only there to inform Prince of some test results.

Meanwhile, as the Purple Rain hitmaker died intestate the battle over his fortune rages on. Under Minnesota law, the estates of people who die intestate are passed to their closest relatives. This entitles all of Princes' six siblings to an equal share of his possessions, regardless of the closeness of their family ties.

A Colorado inmate's bid to inherit the $300m estate was recently withdrawn after DNA results revealed that he is not related to Prince and there is a 0.0% chance he's Prince's son. Carlin Q. Williams, 39, had filed legal documents claiming to be the late superstar's lovechild, stating his mother had had a fling with the singer in 1976.