MINNEAPOLIS (AP) _ A search warrant filed in the investigation of pop superstar Prince's death says the singer routinely got vitamin B12 injections so he could ``feel better'' before performances.

Several search warrants were unsealed Monday near the one-year anniversary of Prince's death of a fentanyl overdose. Authorities haven't yet charged anyone in the case.
The B12 detail was included in a detective's affidavit seeking one of the search warrants.

The detective wrote that Prince didn't have a regular doctor, and instead saw various doctors arranged by his managers who would give him B12 injections before performances.

The injections are promoted online as a treatment for vitamin deficiencies that can lead to symptoms such as anemia.