The X-Men and Newsroom star has told Entertainment Weekly Radio she had to fork out her own hard-earned cash in order to make a guest appearance on the female-driven spinoff starring Cate Blanchett, Anne Hathaway and Sandra Bullock.

"It actually cost me money to be part of Ocean's Eight," she said.

"There's a whole scene at the Met Ball and they were like, oh, do your own glam. So I got the dress and all that and usually you submit the bills for it because I'm part of your movie. And they were like, oh, no, the bills come right back to you."

The revelation will no doubt raise eyebrows in Hollywood, given the franchise behind Ocean's Eight has grossed hundreds of millions of dollars worldwide.

Munn's expenses make Rebel Wilson's measly $3000 cheque for appearing in multi-million dollar hit Bridesmaids look generous in comparison.

Despite having to pay for her own on-set make-up and costume, Munn said there's no hard feelings and she's excited to see the finished product given the lead roles all belong to women.

"It's going to be amazing," she said. "You see all these guys who keep falling up. They do crappy movie after crappy movie, and they keep getting more chances. If you've got a female lead or a female director, you've got one shot."

Ocean's Eight will explore how the estranged sister of Danny Ocean (George Clooney) attempts to pull off a major heist at New York's annual Met Gala. Filming kicked off in October 2016, with the film set to hit cinemas mid next year.