Police revealed the initial results of George Michael's autopsy, saying that it was "inconclusive" and that more tests would need to be done.
Thames Valley police announced the initial autopsy did not reveal a specific cause of death -- adding that further testing would take several weeks, The Hollywood Reporter reported.
The legendary pop star's death on Christmas Day has been categorized by authorities as "unexplained but not suspicious." There was no evidence of foul play.
The singer was found dead of what is believed to be heart failure.
"It is with great sadness that we can confirm our beloved son, brother and friend George passed away peacefully at home over the Christmas period," Michael's publicist confirmed in a statement, The New York Times reported. "The family would ask that their privacy be respected at this difficult and emotional time. There will be no further comment at this stage."
Michael rose to fame as half of the pop duo Wham! in the 1980s before breaking out of his teen idol persona and becoming a prolific and hugely successful solo artist with hits like "Freedom 90" and his hit album "Faith."