The Serious Fraud Office has arrested four people and laid more than 100 charges over the collapse of Five Star Finance Group.
Five Star was placed in receivership in 2007, then liquidation in 2008, owing investors in excess of $85 million.
The accused are former directors Nicholas Kirk, Marcus MacDonald and Anthony Bowden, and Neill Williams, who was heavily involved in the management of the company.
The charges relate to loans totalling $50 million, which the SFO says is largely unrecoverable.
The charges concern related party lending between 2003 and 2007, in which the accused allegedly intentionally applied funds in breach of the company's trust deed and dishonestly used documents to obtain a benefit.