Australian crew members working on the big budget Hollywood movie Thor: Ragnarok on the Gold Coast are on the same casual rates as a decade ago, their union says.

Media Entertainment and Arts Alliance's Queensland director Michelle Rae says the "market" rate, which is higher than the award rate, has not increased in 10 years and a workplace agreement with international productions needs to be struck.

She says many in the industry believe international producers are "double dipping" by accepting payroll tax concessions and then negotiating on wages and conditions after they've agreed to a government deal.

"If we had an agreement with the market rate included, then it wouldn't be an issue and the producers would know what their budget is before they start talking to the government," Rae said.