MINNEAPOLIS — Court documents unsealed in the investigation into Prince’s death suggest a doctor and a close friend helped him improperly obtain prescription opioid painkillers, but they shed no new light on how the superstar got the fentanyl that killed him.

The affidavits and search warrants were unsealed in Carver County District Court as the yearlong investigation into Prince’s death continues. The documents show authorities searched Paisley Park, cell phone records of Prince’s associates, and Prince’s email accounts to try to determine how he got the fentanyl, a synthetic opioid drug 50 times more powerful than heroin.

The documents don’t reveal answers to that question, but do provide the most details yet seen on Prince’s struggle with addiction to prescription opioids in the days before he died.