The NSW Independent Commission Against Corruption (ICAC) will conduct a public inquiry into the dealings of former Ausgrid engineer Phillip Cresnar as part of Operation Jarah from next week.

Assistant Commissioner Theresa Hamilton will investigate allegations Mr Cresnar disclosed confidential information to contractors and others in relation to his official functions at the NSW state-owned electric distribution company.

The ICAC will allege that Mr Cresnar solicited benefits from contractors over a five-year period in return for his assistance in the awarding of Ausgrid contracts and giving approval to contract variations, according to a statement from ICAC.

A spokesperson for Ausgrid confirmed they have been co-operating with the ICAC inquiry. "Ausgrid takes its responsibility for spending public money very seriously. We will continue to provide our full co-operation to the ICAC in any efforts to prevent and pursue wrong-doing," the spokesperson said.

Mr Cresnar was unable to be contacted for comment.

An ICAC spokeswoman said they were unable to give any further comment to the ongoing investigation.

The inquiry will run for five days starting Monday, January 19.