It's being reported that pills found at Prince's home following his death in April had been mislabelled.

Investigators who searched his property have told the Minneapolis Star Tribune that he may not have even known he was taking the dangerously powerful drug called Fentanyl.

Fentanyl is a synthetic opioid, around fifty times more powerful than heroin.

Records show Prince had no prescription for any controlled substances in the state of Minnesota in the 12 months before he died and it remains unclear how he obtained the drugs.

The singer apparently only weighed 8 stone when he died in an accidental overdose.