Prince’s cause of death still remains a mystery, but Dr. Drew Pinsky believes the singer may have died from an accidental drug overdose. Dr. Drew recently opened up about the “Purple Rain” singer’s untimely death, shedding doubt on reports that Prince was suffering from the flu.

“They don’t land planes for the flu,” Dr. Drew said (via Billboard). Last week, TMZ reported that a plane Prince was on was forced to stop and the singer was hospitalized and released a few hours later. At the time, a rep said Prince had been diagnosed with the flu.

TMZ later reported that Prince was seen several times picking up a prescription at a local Walgreens pharmacy. Sources told the outlet that people in the store were worried about the singer because when he picked up a prescription Wednesday evening he seemed nervous and looked frail. Prince died Thursday at the age of 57.

Dr. Drew explained that Prince’s sudden respiratory distress could have been caused by a “combination of opiates and Benzodiazepines,” which is primarily used to treat anxiety. “[It] makes you stop breathing and you die,” he said. “It’s easy for that happen with that combination even as prescribed.”

“Although opiates figure into this story, it doesn’t really sound like an addiction story,” he continued. “Even if it ends up being drugs that caused him to stop breathing, I would put it more in the accident category than the addiction category. But still, an otherwise healthy middle-aged man with hip pain should not be on opiates chronically. Period.”

An autopsy on Prince was completed Friday, but the results aren’t expected to be released for several weeks. On Saturday, it was reported that the singer’s remains had been cremated and his family held a private memorial at his Paisley Park home in Chanhassen, Minnesota.