Prince died after accidentally taking a fatal overdose of painkillers, a post-mortem examination has found.
Midwest Medical Examiner's Office's report said the singer had taken the opioid Fentanyl and his death was an accident.
The 57-year-old music superstar was found dead at his Paisley Park estate near Minneapolis on April 21.
Chief medical examiner Dr Angelique Quinn Strobl's report was unable to confirm when the overdose was taken.
The one-page report said Prince was dressed in black at the time of his death and was wearing a black cap.
The medical examiner's office said its investigation into Prince's death had now finished and it was unable to make any further comments.
A spokesman for Carver County Sheriff's Office said its investigation was continuing but was unable to give any further details about its progress.