Prince had a high level of fentanyl in his body when he died at the age of 57 in April 2016, according to a previously confidential toxicology report obtained by the Associated Press on Monday, March 26. The report revealed that the concentration of the synthetic opioid ? which is 50 to 100 times more potent than morphine ? in the ?Purple Rain? singer?s blood was 67.8 micrograms per liter.