Actor Mel Gibson has been caught on tape making racist and sexist remarks towards his Russian ex-girlfriend and baby mama Oksana Grigorieva.

TMZ.com reports that in the recording, Gibson used a highly offensive term levelled against African Americans.

"You look like a f...ing pig in heat and if you get raped by a pack of niggers it will be your fault," Gibson allegedly told Grigorieva, according to TMZ.

The website has verified that it was Gibson on the tape secretly recorded by Grigorieva.

The ex-lovers is in the middle of a custody battle for their daughter Lucia. The secret recordings were given to the Los Angeles judge who was in charge of their dispute.

In 2006, Gibson was arrested in Malibu for drunk driving and made anti-Semitic remarks: "F...ing Jews.... The Jews are responsible for all the wars in the world."

Religious leaders and high-powered members of Hollywood slammed he remarks and it took Gibson years before he was able to fix his battered reputation.

His most recent rantings disappointed the National Association for the Advancement of Coloured People (NAACP). Leon Jenkins, the organisation's president said it is unfortunate that Gibson "has made his millions off of women, African-Americans and Jews", but holds "such racist, sexist, and anti-Semitic feeling against people who have admired and respected him for decades".

"An apology is insufficient given his history of racism, sexism and anti-Semitism," Jenkins told TMZ.

"No amount of words will change his image as an out-of-date and out-of-control racist.

"Only by a sustained period of positive acts can his legacy be redeemed."