Prince: Doctor Under Fire Mysteriously Left Practice Days Ago

The doctor who law enforcement is targeting in the Prince investigation abruptly left the facility where he practiced ... and no one will say why.

Dr. Michael Schulenberg was at Paisley Park when Prince died, and as we reported, authorities obtained a search warrant to seize the doctor's medical records and, more specifically, prescriptions he wrote for the singer.

As we previously reported, Dr. Schulenberg saw Prince on April 7th and April 20th -- the day before Prince died. He also wrote prescriptions for Prince that were to be filled at Walgreens ... the pharmacy Prince visited 4 times in the last 7 days of his life.

Turns out ... Dr. Schulenberg worked at North Memorial Physicians clinic in Minnetonka, Minnesota. The facility is 10 miles from Prince's estate. A rep from the facility told TMZ ... the doctor left "in the last few days" but would not say if he was terminated or just quit.

Before Dr. Schulenberg worked at North Memorial, we're told he practiced at Ridgeview Hospital and Prince's bodyguard told cops he took Prince to that hospital in 2014 and 2015.

Dr. Schulenberg has a clean record, and even got an MBA in addition to his MD.