The 'Careless Whisper' hitmaker passed away from heart failure at his home in Goring-on-Thames, Oxfordshire, South East England, on Christmas Day (25.12.16) aged just 53, and sources have now claimed the star "used heroin" and had been rushed to hospital earlier in the year for treatment after an overdose.
The source told The Daily Telegraph: "He's been rushed to A&E on several occasions. He used heroin. I think it's amazing he's lasted as long as he has."
The news comes as PR chief Gary Farrow - a close friend of the 'One More Try' singer - told The Sun newspaper that "easy access to drugs" ultimately caused the death of the prolific talent.
He said: "I believe easy access to drugs was the cause of his problems. I thought George was too bright to get involved with illegal substances, but once this disease gets hold of you it's hard to fight it."
According to sources, cardiac arrest - which was the cause of death according to George's manager Michael Lippman - is common amongst heroin users.
Michael said on Monday (26.12.16) that he received a call telling him that Michael had been found "in bed, lying peacefully" and that there was "no foul play whatsoever". He added that Michael's death from heart failure was unexpected.
Meanwhile, George's publicist announced his death in a statement around 11pm on Christmas Day, saying: "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. The family would ask that their privacy be respected at this difficult and emotional time. There will be no further comment at this stage."
A statement from Thames Valley Police read: "Thames Valley Police were called to a property in Goring-on-Thames shortly before 2pm Christmas Day. Sadly, a 53-year-old man was confirmed deceased at the scene. At this stage the death is being treated as unexplained but not suspicious. A post mortem will be undertaken in due course. There will be no further updates from Thames Valley Police until the post mortem has taken place."