Richard Hatch's trial began earlier this month

Mr Hatch is accused of failing to pay tax on the money he won on Survivor in 2000, and is charged with using money earmarked for a charity on himself.

He shot to fame as one of 16 contestants marooned on the Malaysian island of Pulau Tiga for the CBS show.

His assertion came on the final day of testimony in Providence, Rhode Island.

Closing arguments are scheduled for Wednesday.

Mr Hatch has denied charges including tax evasion and bank fraud.

If convicted, he could face a fine of up to $1.35m (�748,000) and up to 73 years in prison.

Tax letters

Mr Hatch told the court he decided not to pay the taxes after discussions with producers, fellow contestants and his accountant, and after receiving two letters from the US tax authority, the Internal Revenue Service (IRS).

The letters told him he had missed a tax deadline, and listed several sources of income, but did not mention his Survivor winnings.

Mr Hatch said it he took the IRS's letter to mean somebody else had paid the taxes, but under questioning from assistant US attorney Lee Vilker, Mr Hatch acknowledged the IRS had warned the list of income might not be comprehensive.

Survivor producer Mark Burnett said earlier in the trial that the contract Mr Hatch signed stated contestants would be responsible for their own tax affairs.

Charity money

Mr Hatch also acknowledged using money donated to his charity, Horizon Bound, to pay for tips for his limousine driver and payments for workers doing construction work on his house.

Mr Hatch's win helped spark the US reality TV boom

He said he was simply reimbursing himself after putting much of his own money into the charity, and added the improvements to his house would benefit Horizon Bound, as the house could be used by the charity.

However, he conceded that he sold the house in 2002 for more than $862,000, and the charity - which was set up to run wilderness trips for troubled young people - did not run any trips.

Since Mr Hatch won Survivor in 2000, the show has become a mainstay of US TV schedules, and begins its 12th series, set in Panama, next month.

Like Big Brother, the format - which was conceived by a British producer but first appeared in Sweden - has been a hit around the world, although a version brought to the UK by ITV in 2001 was less successful, only lasting for two series.

Earlier in the trial, Mr Hatch's lawyer Michael Minns said some of Mr Hatch's fellow contestants had asked friends to try to sneak food into their tropical location. CBS refused to comment on the allegation.