Mel Gibson's anti-Semitic remarks have caused a furore

The decision was made after the actor's drink-drive arrest, during which he made derogatory remarks about Jews.

The three-page letter endorsed the Republican candidate's campaign and praised his stand for "principles that might not be politically correct".

The politician's spokesman said he was "disillusioned" by Mr Gibson's arrest.

"Tom saw the news and the situation as it was unfolding with Mel Gibson and made a conscious decision to direct people not to use the letter any further," campaign spokesman Stan Devereaux said.

The letter has been sent to potential donors four times over the past year.

Mr Devereaux added that there had been no plans to use it again, even before Gibson's arrest.

'Impressed'

In the letter, the actor said he was impressed by Senator McClintock when he ran against Arnold Schwarzenegger to be governor of California in 2003.

"When someone like Senator Tom McClintock steps forward and is willing to fight for basic American principles for all Californians, I intend to stand with him," Gibson wrote.

Mr Gibson is expected to appear in court on charges related to drink-driving on 28 September.

He is accused of driving under the influence, having a raised blood-alcohol level and having an open alcohol bottle in the car.