EXCLUSIVE: Steve McQueen's Family in $70Million Art War — Granddaughter Says Icon's Jackson Pollock Painting Was 'Stolen' After Botched Motorcycle Swap

The granddaughter of the late Hollywood icon Steve McQueen is trying to claw back a Jackson Pollock drip painting – worth a whopping $70million or more – that she claims was stolen from the hunky Bullitt star, RadarOnline.com can reveal.

Molly McQueen, 38, claimed her famous speed-loving grandpa agreed to swap the valuable painting for a motorcycle and a piece of property in Latigo Canyon near Malibu with Rudolph and Pamela Borchert.

The Getaway hunk transferred the painting to the married couple, but the deal fell apart after one of the Borcherts "crashed" the motorcycle, and the title deed for the Latigo Canyon site was never transferred, the lawsuit states.

"Steve McQueen made a demand for the return of the Pollock painting within a reasonable time thereafter," the lawsuit states. "However, the Borcherts failed to return the painting to Steve McQueen."

After the King of Cool suffered a heart attack and died at age 50 in 1980 following surgery to remove tumors from his neck and stomach, "the Borcherts failed to return the painting to his estate," states the claim filed in August in Los Angeles Superior Court.

Since then, "the Borcherts have passed, their respective estates have settled, and the Pollock painting is now in the possession of Brent Borchert, their son," who is the one being sued, said Molly's lawyers.

While the swap occurred decades ago, Molly, daughter of the Towering Inferno actor's daughter Terry Leslie McQueen, who died of respiratory failure at age 38 in 1998, claimed she only learned about the "wrongful possession" of the painting in March and that the statute of limitations for a claim has not expired.

Meanwhile, Brent Borchert, 58, denied the claim, branding it as "frivolous" and "totally and completely without merit" and charging that it was "brought for the sole purpose of harassing [the] Defendant," according to court documents.