The custody battle between Mel Gibson and his former girlfriend Oksana Grigorieva over their eight-month-old daughter appears to have reached a whole new level of low.

Multiple reports cite audio tapes in which the “Passion of the Christ” star uses a slew of derogatory and racial slurs throughout profanity-laced tirades.

RadarOnline claims to have heard the tapes, and say that not only did Gibson call Grigorieva a “c**t” and “whore” in a tape that she apparently recorded without his knowledge, but he also dropped the N-bomb with the comment, "You look like a f*king pig in heat and if you get raped by a pack of ni**ers it will be your fault."

The tapes are under seal amid the custody proceedings in the L.A Superior Court, but RadarOnline says they also heard a malevolent message Gibson left on the mother of his child’s voice mail, referring to her as “a psycho c***t” – all while their baby can be heard screaming in the background. In another verbal attack, Gibson allegedly threatened to “come and burn the f***ing house down.”

Numerous “incendiary” e-mails from Gibson are also reported to exist.

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A rep for Gibson could “not confirm the credibility or authenticity” of the alleged tapes, and Grigorieva’s legal representative did not respond for comment. Last week, the feuding former flames filed dueling restraining orders against each other, although the documents remain under seal.

If the salacious comments attributed to the 54-year-old actor are proven to be accurate, the outcome could be much more damaging than a simple wave of public indignation.

“If it is true that Mel threatened to burn her house down, that could be considered a criminal terrorist threat. A terrorist threat can be anything designed to induce harm or kill another individual, it doesn’t have to come from Al-Qaeda to be classified as terrorism,” explained Santa Monica-based Criminal Defense Attorney, Steve Cron. “There is a real possibility that the police department or a prosecuting agency could take action.”

The Department for Child and Family Services (DCFS) is already planning to send two investigators to Grigorieva's home to see their young daughter and interview both parents.

"They may decide that both parents are unsuitable and then give the baby to a grandparent," a DCFS insider tells Pop Tarts. "This has become a real mess."

This isn't the first time Gibson has come under fire for making racist remarks, and nor is it the first time he has been recorded doing so. In 2006, he was busted for a DUI in Malibu and embarked on an anti-Semitic screed, in which he asked the officer if he was Jewish and said that the “Jews are responsible for all the wars in the world” – the entire exchange was audio taped by the sergeant handling the situation.

On that note, a number of members in the Jewish community are probably not surprised by the reports that Gibson, who admitted to “shame,” apologized and went to rehab over the 2006 incident, has been exposed for making even more alleged racial insults.

“I wish I was more surprised. Given Mr. Gibson's history of comments that are degrading to cultures and religions different than his own; there is little reason to believe that in the heat of passion he may say things that he might later come to regret,” L.A-based Rabbi Michael Barclay said.

Gibson’s alleged use of the “N-word” is also being blasted.

"An apology is insufficient given his history of racism, sexism and anti-Semitism,” the President of the Los Angeles chapter of the National Association for the Advancement of Colored People (NAACP) Leon Jenkins, told TMZ. “No amount of words will change his image as an out of date and out of control racist."

Meanwhile, Katherine Hull of Rape, Abuse and Incest National Network (RAINN) said bluntly, “If that's his attitude about who is to blame for a rape, I hope he never ends up on a jury.”

However, the Worldwide Organization for Women (WOW) which "promotes women’s understanding of their inherent worth and crucial role in society,” has much larger fish to fry.

“Last I heard, free speech is protected. If women want to ‘punish’ Mel Gibson, they can individually not fund him by not attending his movies, etc,” WOW spokeswoman Abbie Vianes told us. “There are bigger villains to catch - like those involved in trafficking women and children, those participating in female genital mutilation, and those raping women and girls in refugee camps.”

Earlier this year, Gibson’s first film in eight years,“The Edge of Darkness” was released, and he has another movie alongside Jodie Foster called “The Beaver” due out later this year.

Might that be the last we see of the Australian actor on the big screen?

“The public can overlook a lot, but this is not something they will tolerate or stomach, this might just be what spells the end for Mel Gibson. If true, not only will he be rejected by the public but by Hollywood,” said Glenn Selig of The Publicity Agency. “If it were a rant against the mother of his children out of anger and included curse words, I think the public could understand--he was angry.  The fact that this rant allegedly includes racial epithets, that's bad. Really bad. And my guess unforgiveable in the eyes of the public and the Hollywood community.”

And it seems he need not even bother even trying to make amends.

“Second time? Same venom? It’s going to be a lot harder for him around Hollywood,” added pop culture expert, Peter Shankman. “I doubt he'll come out with an apology. At this point, no one's going to believe him.”

Yet according to another expert, Hollywood has a habit of forgiving and forgetting.

“I do not think Mel could really tarnish his image anymore than he has already because we all know what to expect,” said Los Angeles-based image consultant Michael Sands. “Hollywood has a selective memory – they’ll probably forgive him."

Deidre Behar contributed to this report