Lewis Hamilton was stopped by police for behaving like a boy racer yesterday, only hours after he had wowed a Melbourne crowd with the fastest lap in Australian Grand Prix practice.

The McLaren driver, who in 2008 became Formula One's youngest-ever world champion, found himself having to make a public apology about his behaviour in Australia for the second year in a row.

"This evening, I was driving in an over-exuberant manner and, as a result, was stopped by the police," the 25-year-old Briton said in a McLaren statement.

"What I did was silly, and I want to apologise for it."

Senior police constable Scott Woodford told Reuters that a 25-year-old male, resident in Switzerland, was stopped at 9.15p.m. in the St Kilda neighbourhood at the wheel of a brand-new Mercedes.

He said the car, which had "accelerated heavily and lost traction to the rear wheels" in making a turn, had been impounded and was due to be released on Monday.

"He's expected to be charged on summons with the offence of improper use of a motor vehicle," said Mr Woodford, who added that Mr Hamilton had a male passenger in the car with him at the time.

"It's fair to say that he was disappointed with the whole incident but I must say he was extremely cooperative throughout."