Prince had an “exceedingly high” concentration of fentanyl in his body when he died, according to a toxicology report from his autopsy.
The music star died alone at 57 inside his Paisley Park estate in Minneapolis on April 21, 2016.
Six weeks after his death, a public report indicated he died of an accidental overdose of fentanyl, a powerful synthetic opioid. But a confidential toxicology report, obtained by the Associated Press, provides a clearer picture.
Prince had a fentanyl concentration in his blood of 67.8 micrograms per litre and in his liver of 450 micrograms per kilogram.
Experts consulted by the AP said it appears Prince was taking fentanyl orally and that the drug had time to circulate before he died.
"The amount in his blood is exceedingly high, even for somebody who is a chronic pain patient on fentanyl patches," said Dr. Lewis Nelson, chairman of emergency medicine at Rutgers New Jersey Medical School.