The 'Careless Whisper' singer was found dead at his home on Christmas Day in 2016 and although it was later determined he'd died from natural causes due to problems with his heart and liver, his former Wham! bandmate is still "uncomfortable" with the official record as he felt his friend was in "good health" at the time.
And Andrew thinks there will always be uncertainty surrounding his death.
Writing in his book, 'Wham: George & Me', he wrote: "That the circumstances of his death seemed unclear only compounded the distress. Without any real closure, the grieving seemed terribly raw.
"A heart condition was recorded as the cause of death, but there were still a number of questions.
"He seemed to be in good health at the time and there are conflicting reports surrounding that night that preceded his passing. It now seems as if we may never know what really happened.
"We don't like our lives being monitored, so when someone dies alone, perhaps there are always answers that remain out of reach.
"It still feels uncomfortable though. God knows what it must be like for George's family."
The 56-year-old singer recalled his agonising grief when he learned his friend had died, because it was so unexpected.
He had just sent a text to George thanking him for his annual Christmas hamper and hoped they would meet up in the New Year and shortly afterwards, the 'Everything She Wants' singer's sister, Melanie, called.
He wrote: "There was certainly nothing to hint at the awful news that followed. 'Andrew, I hate to tell you this' said Melanie. 'But George has died'.
"The news hit me like a punch in the gut.
"It was as if my world had been pulled out from underneath me. I felt overwhelmed and couldn't quite comprehend what was being said. The details and hows and wheres rushed by.
"My best friend had died on Christmas Day and now his sister was having to tell me on the phone.
"I can't imagine how hard that must be for her to have to call so many people and tell them the dreadful news over and over.
"But Melanie managed to hold herself together and delivered the details with great dignity.
"I put down the phone and, doubled over with grief, began to sob."
