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.
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Despite the stories of Michael’s admitted drug use and the rumors surrounding his sudden death, the crowd gathered had only positive memories about the former Wham! frontman and reluctant pop star and idol.
Michael (born Georgios Kyriacos Panayiotou) launched his music career in the 1980s as a band member of Wham! with childhood friend Andrew Ridgeley. The duo released hits including “Last Christmas,” “Wake Me Up Before You Go-Go” and “Careless Whisper.”
In 1987, Michael released his first solo album, Faith, which sold over 25 million copies and catapulted him into success. His second album, Listen Without Prejudice, Vol. 1 — which featured the song “Freedom ’90” — celebrated its 25th anniversary in September 2015.
In the days since his death, fans have also been streaming and buying his songs and albums at a rate not seen in Michael’s career in years, according to Forbes. Less than 24 hours after his death, Michael’s solo discography saw more than a 3,100 percent increase in plays on Spotify globally.
Michael had been working on releasing an album for next year with producer Naughty Boy, the BBC reported earlier this month.