There is “no reason to believe” that Prince’s death was suicide, the sheriff of the Minnesota county where the singer had his home has said after a post-mortem.
There was no sign of trauma on his body, Carver County Sheriff Jim Olson said.
Prince, 57, was found dead in a lift on his Paisley Park estate on Thursday.
Tributes have been paid around the world to the enigmatic musician, who sold more than 100m records.
His innovative music spanned rock, funk and jazz. He was at his peak in the 1980s with albums like Dirty Mind, 1999 and Sign O’ The Times.
The sheriff warned that full results from the post-mortem could take several weeks, and the incident was still under investigation.
There was no one in the residence at the time except Prince and some of his staff, Mr Olson said.
The singer had been rushed to hospital in Illinois last Friday, while flying home from a concert in Georgia, but was treated and released a few hours later.