The Independent Commission Against Corruption (ICAC) will today start handing down its findings into inquiries involving former New South Wales Labor ministers, with some of them likely to face fraud charges.

The ICAC has held four highly publicised inquiries into prominent Labor figures, including former ministers Ian Macdonald and Eddie Obeid.

The six-month spectacle that played out before two often-full public galleries has been described as the most significant corruption inquiry in the state's history.

Commissioner David Ipp will give his findings on Operations Jarilo, Indus and Jasper to Parliament today and the speaker will then release them to the public.

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Since the ICAC inquiries began, Mr Obeid and Mr Macdonald have been expelled from the Labor Party for bringing it into disrepute, however they continue to deny any wrongdoing.

If Mr Ipp makes corrupt findings against the men or any other witnesses, they may be referred to the DPP to consider charges such as fraud, misleading the ICAC and misconduct in public office.

Jasper - mining licences

LtoR Former NSW ministers Eddie Obeid and Ian Macdonald. ( AAP )

Operation Jasper investigated allegations Mr Macdonald rigged a 2008 tender process when he was mining minister to put the Obeid family and their associates in a position to profit $100 million.

It was alleged that Eddie Obeid, his son Moses and Mr Macdonald conspired to "...effect a fraud on the people of New South Wales" and that their conduct was "corruption on a scale probably unexceeded since the days of the Rum Corps".

The inquiry heard Mr Macdonald granted a lucrative coal mining licence over land owned by the Obeids in the Bylong Valley and that the Obeids encouraged their friends to buy up land in the area and secretly hid their involvement in mining projects though complex company structures.

It gave a glimpse of the lavish lifestyle of Mr Obeid and his nine children as well as the power he had when he was in Parliament.

Mining magnate and coal investor Travers Duncan last week lost a last-minute attempt in the High Court to stop the release of any adverse ICAC findings against him.

Jarilo - business deals and an escort called Tiffanie

Operation Jarilo looked at allegations accused murderer Ron Medich and former boxer Lucky Gattellari offered Mr Macdonald incentives to arrange business meetings.

The incentives include the services of a prostitute called Tiffanie.

The 2011 inquiry heard that in 2009 Mr Macdonald had responsibility for Energy Australia and Country Energy, firms which Medich was interested in doing business with.

Medich is soon to face a committal hearing after being charged over the murder of businessman Michael McGurk.

Eric Roozendaal ( AAP: Paul Miller )

Indus - the new car

Operation Indus, which opened in 2012, aired allegations former roads minister Eric Roozendaal got a $10,000 discount on a new car from Mr Obeid's family as a bribe.

Mr Roozendaal, a former treasurer, told the ICAC he is not very good with his personal finances.

He has since resigned from Parliament, stating that the ICAC had nothing to do with his decision.

Acacia - it's not over yet

Findings into a fourth inquiry - Operation Acacia, which looked at the Doyles Creek coal exploration licence Mr Macdonald granted without a tender to union boss John Maitland and others - are expected in August.

The licence was issued on Christmas Eve in 2008.