By Dave Quinn
December 30, 2016 at 10:28 AM EST
Samir Hussein/Redferns via Getty Images

This article originally appeared on

Five days after the shocking death of George Michael, the 53-year-old singer’s cause of death is still unknown.

According to a statement released by the Thames Valley police, a post-mortem examination as part of the investigation into Michael’s death carried out on Thursday was “inconclusive.”

“The cause of death is inconclusive and further tests will now be carried out,” the statement reads. “The results of the tests are unlikely to be known for several weeks.”

“Mr. Michael’s death is still being treated as unexplained but not suspicious,” police add.

Michael was found dead in his home on Christmas Day. His rep told PEOPLE and Entertainment Weekly the “Last Christmas” singer had died of heart failure. Michael’s publicist confirmed the passed away “peacefully.”

As of Wednesday, fans and neighbors continued to gather outside the back of Michael’s house in Goring-on-Thames, Oxfordshire — leaving flowers, teddy bears, cards and photos piled up along its exterior wall.