Prince: Medical Examiner Says Fentanyl Overdose

Prince died from an opioid overdose ... it's now official from the Midwest Medical Examiner's Office, and the drug is even more powerful than Percocet.

The M.E. performed toxicology tests on the singer and determined the singer died of an accidental overdose of Fentanyl -- a powerful synthetic opiate that is more potent than morphine ... often used for cancer patients to deal with severe pain.

Fentanyl is often used to treat people who have developed a tolerance to less powerful opiates such as Percocet and morphine.

And this is important ... there were several reports Prince had either AIDS or HIV, but the report says there were no "other significant conditions" that led to his death ... clearly refuting the stories.

According to the report ... Prince was discovered fully dressed ... wearing a black cap, black shirt, gray undershirt, black pants, black boxer briefs and black socks.

Also interesting ... Prince weighed a petite 112 lbs and stood 5'3" at the time of his death.

We broke numerous stories -- Prince was addicted to Percocet. As we first reported, Prince's private jet was forced to make an emergency landing when the singer almost died after ODing on Percocet 6 days before he was found dead in an elevator.

Prince had made at least 4 trips to a local drugstore in the week preceding his death ... to fill prescriptions.

His addiction was so bad his people called a rehab doctor in California to get him emergency help. The doctor's son flew out to Minnesota and was in the Paisley Park compound -- with a backpack filled with synthetic opioids -- when the 57-year-old singer was found dead. The doctor's son, who is not himself a doctor, denies giving Prince any of the pills.