A law enforcement official who is close to the investigation into Prince’s death told the AP that the singer died of an opioid overdose, the news service reports. The official spoke anonymously because he was not authorized to talk to the media, the report notes.

Prince was found dead April 21 at his Paisley Park estate in the Minneapolis area. He was 57.

“The findings confirm suspicions that opioids played a role in the musician’s death,” the AP reports. “After he died, authorities began reviewing whether an overdose was to blame and whether he had been prescribed drugs in the preceding weeks.”