George Michael Cause Of Death: Did Ex-Wham! Singer Overdose? Police Question Boyfriend Fadi Fawaz

The investigation into George Michael's death has been taken over by a major crimes unit as authorities suspect that the ex-Wham! singer died from a drug overdose, according to the Sun. The 53-year-old was found dead at his home in Oxfordshire on Christmas Day.

Michael's boyfriend Fadi Fawaz has been questioned in connection to the singer's death. While Michael's death is still being treated as “non-suspicious,” detectives from the Thames Valley Police Major Crime Unit are leading the case after a post-mortem proved inconclusive.

“The investigation is now picking up a bit of speed," a source told the Sun. “Officers from the Major Crime Unit have begun asking questions of those who were in the area at the time George died and the days before."

The source went on to add: “They want to build up an idea of what George’s last seven days were like and who came and went... These individuals now handling the day-to-day inquiries have worked on some very serious crimes so are well placed to assist with this.”

Authorities believe that a toxicology test could shed light on a possible cause of death. Earlier reports claimed that Michael died of heart failure.

The "Careless Whisper" singer has had a well-documented history of drug abuse, but recent reports of heroin use were shot down by his family.

However, a retired senior police source told the Sun: “Given his history, there must be a possibility that drugs, illegal or otherwise, could have been involved in his death.

“Because of his high profile and wealth it makes absolute sense for the Major Crime Unit to investigate the full circumstances while they wait for the ‘tox’ tests to come back," the officer reportedly said. “It does not mean that he did die from drugs but until it is proved otherwise they cannot rule it out and must investigate appropriately.”

As the investigation into Michael's death proceeds, more details about his personal life has emerged. According to a report Thursday, Michael was reportedly frightened by the suicides by members of his immediate family in the past.

According to the Mirror, Michael hid his homosexuality from his mother, who feared he had inherited the "gay gene," fearing the suicide of his uncle Colin on Michael’s birthday in 1963 and the subsequent suicide of his grandfather.

“My mother had this fear of me being gay,” Michael said in an interview in 2007. “She had this definite fear that I was going to be like her brother. She thought it meant I wouldn’t cope with life.”