The former chief executive of one of Australia’s biggest Aboriginal corporations, who is accused of a $350,000 rip-off from his former employers, has signalled he intends to use the lack of action against him by the Federal regulator as a defence in a legal bid to get the money back. The Gumala Corporation, which manages millions of dollars of iron ore royalties from Rio Tinto on behalf of the Banyjima, Innawonga and Nyiyaparli peoples, is chasing former boss Steve Mavrigiannakis for hundreds of thousands of dollars to which it says he was never entitled to.