MINNEAPOLIS – Prescription drugs were discovered at Prince’s home when the musician was found dead in his Paisley Park complex in suburban Minneapolis, a law enforcement official told The Associated Press on Thursday.

The official spoke on condition of anonymity because the person was not authorized to speak about the ongoing investigation into Prince’s death. The official did not elaborate.

ABC, NBC, CBS, and CNN, citing unidentified law enforcement sources, reported that prescription painkillers were found on the 57-year-old musician and in his home. The Star Tribune, also citing unnamed sources, reported that prescription pills were found but that it wasn’t clear whether they had been prescribed to Prince.

Prince died April 21. An autopsy has been performed, but results weren’t expected for three to four weeks. The search warrant for Prince’s Paisley Park home and studio – carried out the day of his death – was filed Thursday under seal at the request of investigators who said it would hamper their investigation if contents were public.

The filing, signed by Carver County Chief Deputy Jason Kamerud, also warned that disclosing details in the warrant could cause “the search or related searches to be unsuccessful” and risk injury to innocent people.

The music megastar’s death came less than a week after reports that his plane made an emergency landing in Moline, Illinois, as he returned after performing in Atlanta. TMZ, citing unidentified sources, reported that Prince was treated for an overdose of the painkiller Percocet.

Airport and public safety officials in Moline have refused to confirm that the plane that made an emergency landing there was Prince’s aircraft, and heavily redacted incident reports released to The Associated Press under a public information request did not identify the person who was treated. Prince’s representatives have not responded to AP’s request for comment on the reports.