George Michael "kept people out" during the final years of his life, according to Boy George.
The 55-year-old singer-songwriter has revealed he was in touch with Michael "on and off" before his death in December, but was "not really" aware of the personal problems he was facing.
The 'Karma Chameleon' hitmaker shared: "I read stuff in the papers. But I never really knew really what – he really kept people out, he was quite private."
George was a rival of the 'Faith' singer during the 1980s, but later came to appreciate his talent.
He told 'Watch What Happens Live': "In the early days, we were competition to each other. Both called George, both made soul music. So in the early days, we were really in competition.
"Then sort of later on, I started to really appreciate him as a musician – you know, right around 'Faith'. I started to really appreciate his talent."
George also set the record straight in regards to rumours the duo bickered about Michael not wanting to come out as being gay.
He said: "We did, it wasn't really a feud. In the '80s, everyone – Peter Burns, me, we all used to be really bitchy about each other. It's like the thing that you did in the '80s with those pop magazines. Now it's the housewives who do it!
"But in the '80s, you just said vile things about everyone."
Michael passed away at his home on Christmas Day (25.12.16) aged 53 and his one-time pop rival was among the many stars who paid a glowing tribute to him in reaction to the news.
He wrote in a lengthy Twitter post: "I am thinking of @GeorgeMichael's family, friends and fans right now.
"He was so loved and I hope he knew it because the sadness today is beyond words. Devastating. What a beautiful voice he had and his music will live on as a testament to his talent. I can't believe he is gone."