A former Ausgrid engineer is being investigated by the NSW corruption watchdog for allegedly receiving kickbacks from contractors over a six-year period.

The ICAC is probing the allegations concerning Phillip Cresnar, who used to work for the state-owned electricity company.

Between 2008 and 2014, Mr Cresnar is accused of soliciting and receiving benefits from Ausgrid contractors and subcontractors in exchange for assistance with the awarding of and variations to contracts.

Mr Cresnar also allegedly disclosed to contractors, and others, confidential information acquired in the course of his official functions, the ICAC said in a statement.

The inquiry is set to start on January 19.