Ever since the acclaimed action movie Mad Max: Fury Road hit theaters in 2015, director George Miller has been talking about his plans for a follow-up. Despite rumors last year that the sequel was close to production, there has been no further news about it. It seems we now have a reason why progress has stalled--Miller is suing the studio.

As reported by Deadline, Miller has taken Warner to court in his native Australia, alleging that the company reneged on paying him a multimillion-dollar bonus for Fury Road. The director claims that the studio agreed to pay him a $7 million bonus if the movie's budget came in at under $157 million. Although it went overbudget, Miller states that it was decisions by Warner that caused delays and cost overruns.

In a statement to Deadline, a Warner spokesman said, "We disagree and will vigorously defend against these claims." The site also notes that the studio attempted to get the case moved outside of Australia, but the country's Supreme Court last week ruled that it would be litigated there.

Mad Max: Fury Road starred Tom Hardy, Charlize Theron, and Nicholas Hoult. It made $378.4 million worldwide and was nominated for ten Oscars, more than any Australian film in history.

In 2015, Miller stated that there were two Mad Max movies in development. "This film was green lit three times and fell over three times over a decade," he said. "We went to shoot with Mel Gibson back in 2001, but then 9/11 happened, and the American dollar collapsed against the Australian dollar close to 30 per cent, so we lost that amount of budget overnight.

"We were then rained out of Australia. The desert rained for the first time in 15 years, and we ended up in South West Africa, Namibia. But in this process, we had dug down deep into the backstory, not only of the characters, but of every vehicle. How the steering wheels became religious artefacts and things like that.

"So we ended up with two scripts, without really trying," Miller added. "We're talking to the studio about it as we speak, but which one of the two stories will happen next, I'm not so sure."