The intelligence officer, whose name has not been revealed, left the service last month after it emerged that his wife was one of five call girls who took part in the sadomasochistic sex session with Mosley, the Formula One racing chief, The Times of London reported Sunday.

Mosley, the son of Sir Oswald Mosley, the wartime British fascist leader, has rejected calls for him to step down as president of the FIA, the governing body of world motor sport, the British newspaper noted.

MI5, the British security agency, denies the orgy was a "sting" set up to discredit Mosley.

"Any suggestion that the service was involved in setting up Mosley is total nonsense," a senior government official said.

Mosley, 68, is one of the most powerful men in world sports. His father was a hate figure who led the British Union of Fascists in the 1930s and 1940s. His mother was the society beauty Diana Mitford, a great admirer of Nazi German leader Adolf Hitler, whose aspirations for world domination led to World War II.