Johnny Depp's $20 million salary dispute could lead to a lawsuit.

The actor allegedly pulled out of starring in a movie about mobster Whitey Bulger last week after he was asked to cut his eight-figure pay day in half by financiers Cross Creek and Exclusive Media, and sources indicate the contentious situation could lead to an expensive court battle.

"Either his team screwed up and left him exposed or Cross Creek is simply reneging on its deal. Someone is suing someone at the end of this," an insider said.

Johnny, 49, closed a pricey deal to star in Black Mass, however, walked away from his role on May 30 when the producers asked him to slash his fee to $10 million, fearing the picture would cost $63 million - $13 million more than the anticipated budget. The troubles don't end there, though, as producers could face trouble after selling rights to the film in international territories on the basis that the Pirates of the Caribbean actor would star. "The second they asked him to take a cut, that was a mistake. They overplayed their hand," a source said.

However, Johnny isn't alone in being asked to cut his salary - co-star Joel Edgerton, who recently starred in The Great Gatsby, was also requested to take a pay cut by Cross Creek.