MINNEAPOLIS — Prince thought he was taking a common painkiller but instead ingested a counterfeit pill containing the dangerously powerful drug fentanyl, a Minnesota prosecutor said Thursday as he announced that no charges would be filed in the musician’s death.

Carver County Attorney Mark Metz said Prince had suffered from pain for years and was addicted to pain medication. While some of the superstar’s associates might have enabled his drug habit and tried to protect his privacy, authorities found “no direct evidence that a specific person provided the fentanyl.”

“In all likelihood, Prince had no idea that he was taking a counterfeit pill that could kill him,” Metz said.

Metz’s announcement came just hours after the U.S. Attorney’s Office announced that a doctor who was accused of illegally prescribing an opioid for Prince agreed to pay $30,000 to settle a civil violation of a federal drug law.