George Michael's boyfriend Fadi Fawaz will be questioned again by detectives as they fear the singer may have died from a drugs overdose on Christmas Day.
The Wham! star's sudden death is still being treated as "non-suspicious" but a major crime unit from Thames Valley Police, who specialise in murders and rapes, has now been brought in to rifle through the file as they attempt to piece together the days leading up to the point George was found dead by his partner at his home in Oxfordshire.
A source told The Sun newspaper: "The investigation is now picking up a bit of speed. Officers from the Major Crime Unit have begun asking questions of those who were in the area at the time George died and the day before. They want to build up an idea of what George's last seven days were like and who came and went."
It was initially claimed the 'Careless Whisper' hitmaker - who was found dead at the age of 53 - died from heart failure but it's now thought the singer, who had an estimated fortune of £105 million, passed away from an overdose of illegal or prescription drugs.
George had a well-documented battle with drug abuse throughout his career and his cousin recently revealed that he was treated for crack cocaine addiction in 2015.
A post-mortem was carried out last week on George's body but it failed to identify the cause of death and now toxicology tests are underway to determine what ended his life.
One retired senior police officer explained to the publication: "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 toxicology results to come back. It does not mean that he did die from drugs but until it is proved otherwise they cannot rule it out and must investigate properly."
Police are reportedly planning to grill Fadi, who dated the singer from 2012 until his death, once again this week, as well as George's housekeeper and neighbours.
Photographers who were working nearby his home over the festive season are also helping police with their investigation but it's not believed anyone is under suspicion.
The exact details of George's funeral are yet to be announced but it's believed he will have two ceremonies - one for friends and family and one for fans - later this month.