A toxicology report from Prince’s post-mortem examination, obtained on Monday by The Associated Press, shows he had what multiple experts called an “exceedingly high” concentration of fentanyl in his body when he died.

Prince was 57 when he was found alone and unresponsive in an elevator at his Paisley Park estate on April  21st, 2016. Public data released six weeks after his death showed he died of an accidental overdose of fentanyl, a synthetic opioid 50 times more powerful than heroin.

A confidential toxicology report obtained by the AP provides some insight into just how much fentanyl was in his system. Experts who are not connected to the Prince investigation said the numbers leave no doubt that fentanyl killed him.