FILE PHOTO: Actor Shia LaBeouf exits the Manhattan Criminal Courthouse following an appearance in New York. Picture: Brendan McDermid/Reuters

Shia LaBeouf has justified calling a bartender a "f***ing racist" by telling a court he was exercising his right to free speech.

The Hollywood star became embroiled in an ugly row with a bartender back in April when he refused to serve the actor more alcohol, but Shia's lawyer says the assault and defamation lawsuit filed against his client is "completely frivolous".

The lawyer is, therefore, asking a California judge to dismiss the case, arguing the employee can't sue Shia because the allegations stem from his exercise of protected free speech, according to The Hollywood Reporter.

In a court filing, Brian G. Wolf claimed the accusation is "not only completely frivolous in nature, but also provides a compelling example of the type of claims which California's anti-SLAPP statute was enacted to prevent".

He said, too, that Shia is only facing these accusations because his "celebrity status turned what would have otherwise been a wholly private encounter ... into a matter of significant public interest".

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Shia's remarks were clearly a matter of opinion, according to his lawyer, who added that they didn't cause the bartender any emotional distress and nor was it an act of assault.

Wolf wrote: "This action amounts to little more than attempted civil extortion."

In fact, he claimed the bartender's behaviour was more threatening than that of his 31-year-old client, who has frequently been in trouble with the law over the last decade.

In his court filing, Wolf explained: "While Plaintiff's feelings may have been hurt by being called a racist by Defendant, '[t]here is no occasion for the law to intervene where someone's feelings are hurt.

"Indeed, Plaintiff's own admitted conduct in threatening to hit Defendant with a Grey Goose bottle was more outrageous than anything that Defendant is alleged to have done. (sic)"