Prince succumbed to an opioid overdose, a law enforcement source told the Associated Press on Thursday, confirming what had been widely speculated since his untimely death in April.

The AP did not identify the official, whom it said was close to the investigation and was not authorized to speak publicly.

Prince died April 21 at his Minneapolis home. In the weeks that followed, reports swirled that the 57-year-old music superstar had developed an addiction to painkillers he was prescribed for hip pain he’d developed from dancing and jumping onstage.

Though the official toxicology report has not been released, enough time has now passed — they usually take roughly six weeks — that it could conceivably be complete.

Investigators are also looking into where Prince may have been getting access to prescription opioid painkillers.