The costume worn by the Titanic star in The Man In The Iron Mark - comprising a shirt, tunic, breeches and coat - was forecast to fetch between £3,000 and £4,000.

But an American collector snapped it up for just £2,300 at Bonham's auctioneers.

Madonna: Half-price dress from Evita

A second costume worn by DiCaprio in the same film sold for £1,400 - £600 less than the lowest forecast.

Meanwhile, a silk floral dress worn by Madonna in four sequences of the film Evita went to a trade buyer for £1,400 - less than half its lowest estimated price of £3,000.

A Bonhams spokeswoman said buyers had been cautious about DiCaprio because he is a relative newcomer to Hollywood.

"We are really happy with the price. He's a young star. There's obviously a sort of interest in his memorabilia. I'm sure it will increase as he gets older," she said.

A prop gun used by Sylvester Stallone in the 1995 film Judge Dredd was sold for £500.