Iron ore magnate Gina Rinehart says a push to bring on more female truck drivers at her Pilbara mines to help them enter the industry has made Hancock Prospecting’s gender pay gap worse because they are some of the company’s lowest paid roles.

The privately held mining company pays its male employees 25 per cent more than women at the median point, and the pay gap narrows to 22 per cent when bonuses, overtime and other financial benefits are included, according to the Workplace Gender Equality Agency.