Pop star George Michael has been cautioned for drug possession after being arrested at a meeting place for gay men.

Michael was reportedly caught with a small amount of cannabis and crack cocaine on Hampstead Heath in north London, reports dailymail.co.uk.

It is the fourth time in three years that Michael has been arrested on drugs charges. Until now he was caught only with soft drugs such as cannabis.

“George has always liked smoking a bit of dope and he's taken it a bit too far sometimes but he's never really gone much further. It's pretty worrying,” said a source.

The singer was released from custody several hours after having been cautioned for possession of drugs Friday. Police have said that no further action will be taken.

Michael has been open about his use of cannabis in the past, saying that he was "constantly trying to smoke less".