He would also find it difficult to travel to the U.S. - where he is still a household name - because of strict restrictions on those with drugs convictions.
Last night a Scotland Yard spokesman said: 'We were called at 1.50am by a member of the public to Hyde Park Corner, where a man was found slumped over the wheel of his car.
'He was not driving and appeared to be OK, but he was arrested on suspicion of being unfit to drive.
'He was taken to a police station and was searched. He was found to be in possession of a controlled substance, a Class C substance.
'He was released on bail to return in March. He was de-arrested on the driving allegation. The substance will be sent for analysis.'
Michael, said to have a £60million fortune, has become something of a recluse in recent years - a far cry from the fresh-faced pin-up who became famous as one half of the Eighties duo Wham! and went on to enormous success as a solo artist.
When he does venture out from his home, rarely in daylight hours, he is usually unshaven and wears loose casual clothing over his increasinglyrotund frame.
Last year Elton John spoke of Michael's reclusive lifestyle saying: 'George is in a strange place. There appears to be a deep-rooted unhappiness in his life.'
Michael, who kept his homosexuality a secret until he was caught in the LA incident, has a long-term partner, Kenny Goss.
The couple, said not to have a monogamous relationship, are thought to be planning to marry under the new civil partnership laws.
