Prince: 'Friendly' Doctor Prescribed Powerful Drugs

Prince was able to get his supply of prescription drugs from more than one doctor ... and at least one of them was a "personal friend" of Prince ... this according to members of the singer's family.

TMZ broke the story ... Prince developed an addiction to Percocet sometime before his hip surgery in 2010, and almost died from an overdose 6 days before his death.

What's significant ... Percocet is a controlled substance, and a single doctor who prescribes an excessive number of pills will be flagged by state and federal authorities. As a result, as in Michael Jackson's case, someone addicted to a drug who needs more than the medically necessary amount will doctor shop.

As we reported, Prince went to a local Walgreens pharmacy 4 times in the week he died to fill prescriptions. Our sources say authorities are on the hunt for the various doctors who prescribed and pharmacies that filled Prince's prescriptions. We're told authorities are also interested in possible aliases the singer might have used.