The committal hearing in the Warrnambool Magistrates Court has been scheduled for three weeks involving indigenous leader Geoff Clark, his wife Trudi and two of their sons, Aaron and Jeremy.

More than 20 witnesses are expected to be available for cross-examination by barristers for the Clarks.

Key among those witnesses is expected to be Michael Fitzgerald, Mr Clark's former right-hand man and the Framlingham Aboriginal Trust special projects/community development officer.

Mr Clark was the trust's administrator for more than 20 years.

It's understood Mr Fitzgerald has made five statements to police during a Victoria Police Major Fraud and Extortion Squad investigation Operation Omega that started in 2012.

Magistrate Charlie Rozencwajg has scheduled a special administrative hearing on Thursday this week in the Melbourne Magistrates Court to ensure the committal hearing goes ahead as expected.

The four family members have been charged with 1170 fraud, theft and deception offences in the $2 million case.

Mr Clark alone faces more than 500 charges.

Most of the charges are alleged to have been committed between 2000 and 2010 and involve between $2 million and $2.5 million.

It is understood the charges laid on August 21 last year completed the investigation stage of the case.

Those charges relate to the alleged misuse of money from the Marr Land Council, managing trusts while a bankrupt and making false declarations about being a bankrupt.

It will be alleged Mr Clark made declarations and gave false testimony about his bankruptcy in relation to assets, including shares in the Framlingham Aboriginal Trust, which allowed him to maintain control of the trust.

The former Aboriginal and Torres Strait Islander Commission chairman has repeatedly indicated he will be plead not guilty to all charges and described the investigation as a witch hunt.

The charges also involve rent from a Cooper Street shed, wages paid to Mrs Clark and in relation to what has become known as "Geoff's Deck".

It's understood about $115,000 was spent on a deck at the Clark family home, including a Merbau wooden decking, bar, kitchen, grill, coffee machine and a pizza oven.

Legal fees of about $550,000 from separate court matters since 2002 are a key feature of the brief.

In 2007, Mr Clark was involved in another court case, involving civil litigation which led to Mr Clark being ordered to pay $20,000 and legal costs of about $200,000 to a plaintiff.

Mr Clark then declared himself bankrupt.

There are 19,000 pages in the Operation Omega police brief of evidence.