NASCAR champion Kurt Busch has made the outrageous claim that his former girlfriend is a trained assassin.

Busch is currently trying to defend himself in court with his ex-partner, Patricia Driscoll, demanding a protective order against the champion driver.

The NASCAR driver is known as the Outlaw on the race track, but in the courtroom he has accused Driscoll of being sent out on missions across Central and South America and Africa.

In her defense, Driscoll has hit out at the claims, labeling them "ludicrous" and suggesting that they originate from the plot of a novel she has been writing, one that Busch is said to have even proofread, according to reports.

"I find it interesting that some of the outlandish claims come straight from a fictional movie script I've been working on for eight years," Ms Driscoll said.

Driscoll's side of the story includes a criminal complaint.

"Ms Driscoll, 37, alleges in a criminal complaint that Busch slammed her head against the bedroom wall of his motorhome at Dover International Speedway, Delaware, which he denies," Sky News reported.

In contrast, Busch told the hearing, "Everyone on the outside can tell me I'm crazy, but I lived it on the inside."

But the story gets more bizarre and disturbing from there, with Busch countering those claims with an array of accusations thrown at Driscoll.

"During his testimony, he also asserted his ex-girlfriend had shown him pictures of bodies with gunshot wounds," Sky News added.

"He said a female character in the film Zero Dark Thirty, about the hunt for Osama bin Laden, was partly based on her."

A court ruling on the no-contact order is expected later this month or in early February.