Kevin Winter / Getty Images North America 1 / 8
Kevin Winter / Getty Images North America 1 / 8

According to law enforcement, Prince's autopsy results show that the 57-year-old musician's unexpected death on April 21 was due to an opioid overdose.

The test results came through on Thursday, stemming from the four-hour autopsy conducted by Chief Medical Examiner Dr. A. Quinn Strobl the day after Prince died, the Associated Press reports. ET reached out to the Midwest Medical Examiner's Office, which said there is "nothing to share at this time."

The report comes after a source told the Star Tribune last month that the painkiller Percocet, an opioid, was present in Prince's body when he was found dead in an elevator at his Paisley Park estate in Minneapolis.

In late April, a law enforcement source also told CBS News that prescription drugs were found in Prince's possession and at his home at the time of his death.

A week prior to his death, Prince's plane was forced to make an emergency landing in Moline, Illinois, where he was transported to a nearby hospital. A source very close to the situation told ET that Prince was battling the flu, which turned into walking pneumonia. In addition, the "Purple Rain" singer was dealing with a hip injury and had a problem with Percocet, according to the source. We are told his issue with the powerful narcotic began years ago, shortly after he underwent hip replacement surgery in 2010.