Mad Max is back - but is Mel?

It's been 24 years since the release of the last movie – but Mad Max is back.

Aussie star Mel Gibson is in the running to reprise his leading role in the fourth instalment of the hugely successful franchise, which will be called Fury Road and is due to begin filming in Sydney in August next year.

But director George Miller, who was at the helm for the previous Mad Max movies, stressed Gibson had not yet been cast and that new faces were likely to feature.

"I'm still in the middle of casting, despite all the stuff we see on the net and so on. I don't even know who the final cast will be," Miller told reporters at a press conference in Sydney on Saturday.

The story for Fury Road is already fully formed and Miller says it will modernise the franchise and take it in a new direction.

The film will be shot in Broken Hill, in outback NSW, and in Sydney.

- AAP