Michael's fears were fuelled when his friend Anselmo Feleppa died of an Aids-related illness in 1995.
"On reflection, he felt it was too close and too personal a journey. It was too personal for Anselmo's family to revisit," the BBC quoted a spokesman for the singer as saying.
The BBC had revealed that details of Michael's interview when the documentary was launched in July.
"George says he does not believe in tests. He says he finds the wait for results too harrowing and that he hasn't had a test since at least 2004 due to his fears it might be positive," said producer Ross Wilson.
The second part of the programme will focus on how HIV is spreading. It will also feature Fry getting HIV test conducted on himself.