There is "no reason to believe" that Prince's death at the age of 57 was suicide, police have declared.

Prince - real name Prince Rogers Nelson - was found dead at his home in Minneapolis on Thursday. Carver County Sheriff Jim Olson has declared that there were no signs of trauma on Prince's body when he was found unresponsive in an elevator at his Paisley Park estate.  

"There were no obvious signs of trauma on the body at all," he said. "We have no reason to believe at this point that this was a suicide." However, he added that it was "still under investigation" as to whether foul play was involved.

He refused to comment on reports that the star had been taking a powerful painkiller before his death. A medical examiner's office spokeswoman declined to say whether any prescription drugs were taken from Prince's home following his death.

Sherrif Olson said his officers carry a medication that can be given to someone suffering a drug overdose, but did not use it during the emergency call to Paisley Park.

TMZ website reported that he had overdosed on a drug called Percocet when his private plane made an emergency landing in Atlanta, Georgia, on April 15, six days before his death.