It has been two years since music icon Prince passed away. But new details surrounding the death of the legend, who was 57 years old when he passed, have revealed Prince had extremely high levels of fentanyl in his blood when he died. 

Emergency responders found the singer unresponsive in an elevator at his Paisley Park estate on April 21, 2016. Toxicology reports revealed he overdosed on the synthetic opioid fentanyl, which is 50 times more powerful than heroin. 

The Associated Press recently obtained the toxicology report showing how much of the drug was in his body. Experts who are not directly involved with the Prince investigation strongly believe the drug is the culprit behind his death. 

"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. 

He said the fentanyl concentrations were "a pretty clear smoking gun."

According to the Associated Press, there were 67.8 micrograms per liter of fentanyl in Prince’s blood. The report also explains that fatalities have been documented in people with blood levels ranging from three to 58 micrograms per liter.

Those who are accustomed to taking opioids build up a tolerance for such drugs, which means there is no particular "lethal level." About a year after Prince's death, search warrants were issued and authorities discovered a number of drugs containing fentanyl at his residence.