Thomson Reuters
Prince performs during the halftime show of the NFL's Super Bowl XLI football game in Miami.
It is not yet clear if the drug contributed to Prince's death, the source also said.
Percocet is a prescription painkiller. The opioid was reportedly found on Prince and in his Paisley Park home in suburban Minneapolis.
A source also told the Star Tribune that Prince was one day away from getting help for an addiction to painkillers when he was found dead in an elevator in his home.
The news comes as both the Drug Enforcement Agency (DEA) and the U.S. attorney's office have announced that they are assisting in the local police investigation of Prince's death.
Representatives for Prince were not immediately available for comment to Business Insider.