Apparently in Australia, it is illegal to discriminate pay based on gender. This law is called the Fair Work Act 2009, where it protects employees from being discriminated against based on their sex, race, caring responsibilities, pregnancy, religion, political opinion and more.
But, it is not the same thing as the gender pay gap.
https://www.9news.com.au/national/gender-pay-gap-myth-why-it-is-more-than-equal-pay-for-the-same-work/815dce7d-eb38-4596-ad64-c0f9261cc95c