Pop star George Michael was arrested in a public toilet in Hampstead on Friday and later cautioned for possession of Class A and Class C drugs.

The 45-year-old’s latest brush with the law happened after a suspicious toilet attendant called police.

Michael has talked openly about his cannabis use in the past, and last year even smoked it during a recorded TV inteview with ITV’s The South Bank Show.

The British pop star has sold more than 100 million records worldwide.

Throughout 2006 and 2007, Michael was regularly in the headlines over various drug related incidents.

He was cautioned twice for possessing cannabis when he was found asleep behind the wheel of his car on two separate occasions.

Questions about Michael’s sexual orientation plagued his career until 1998, when the pop star was arrested in a Californian public toilet for “engaging in a lewd act.”

He publicly came out after the incident, and was open about his relationship with former cheerleading coach Kenny Goss.

In January publisher HarperCollins announced they have secured the rights to an autobiography by Michael.

Although neither publisher nor publicist would reveal how much the star is being paid for the book, industry watchers said it was certain to be millions of pounds.

Michael is to write the book “entirely” by himself.

The as-yet untitled book, which HarperCollins called “one of the biggest book deals ever concluded in UK publishing,” is due to appear in autumn 2009.