Prince: Cops Search Singer's Pharmacy for Clues

Authorities descended on a Walgreens near Paisley Park and served a search warrant on the pharmacy, TMZ has learned, looking for a prescription paper trail that could unravel the cause of Prince's death.

It's the same drug store chain where Prince made 4 Rx runs in the week leading up to his death.

We're told investigators made their move Thursday. Once inside, they beelined it for the pharmacy and spent several hours combing through records.

As we reported, authorities are especially interested in Percocet ... the drug that triggered a near-fatal OD 6 days before Prince's death. They're also looking for other prescriptions in Prince's name or identifiable aliases.

We're told investigators are also targeting other pharmacies and doctors who may have helped Prince procure meds.