Prince's autopsy revealed he died of a severe overdose of the synthetic opioid that is 50 times stronger than heroin.
Prosecutors add that no one will be criminally charged in the singer's death.
There's also photos from inside Prince's Paisley Park vault and a Sinéad O'Connor police interview from May 2016 where she alleged that Prince had a history of drug use and violence towards women. Carver County Attorney Mark Metz confirmed the news, stating during the press conference,"The evidence suggests that Prince took counterfeit Vicodin, containing fentanyl".
Associates at Paisley Park told investigators that Prince had been "going through withdrawals, which are believed to be the result of the abuse of prescription medication", according to an affidavit unsealed in state court previous year.
Metz closed the case and said there was no evidence that Prince or his associates knew that he was taking deadly drugs which contained fentanyl. Officials said the doctor's Percocet pills were not responsible for Prince's death.
Prince's doctor, Michael Todd Schulenberg, reached a $30,000 settlement in a federal civil suit after he was accused of illegally prescribing an opioid painkiller to Prince, the U.S. Attorney's Office announced Thursday.
Johnson "continues to deny that he had anything to do with the death of his close friend, Prince", Johnson's attorney F. Clayton Tyler said in a statement.
Dr Schulenberg admitted no liability as part of the settlement and has maintained he did not prescribe drugs to anyone with the intention they be redirected to Prince.
Prince's death shocked the world and led to a protracted battle among his siblings and half siblings over who would inherit his estate, estimated to be worth hundreds of millions of dollars in unreleased recordings and music rights.