A former Ausgrid worker at the centre of a $300,000 kickbacks inquiry told a contractor he "fudged the figures" so it would win a contract, according to a secretly-taped phone call.

Phillip Cresnar appeared at the Independent Commission Against Corruption on Thursday to face allegations he solicited cash and gifts from contractors in exchange for helping them win multimillion-dollar contracts for excavation and cable-laying work.

In a February 7 phone call last year with one contractor, his friend Denis Twomey from Murray Civil Works, Mr Cresnar said another contractor was "slightly cheaper than you but I fudged the figures" for a "cable pull [job] you did this morning".

But the former Ausgrid project engineer told the ICAC that he did not remember what he meant by "fudged" in that context and "I'd have to go into the figures ... to see if I was lying to him [Mr Twomey] or not".

In another phone call, in October 2013, he told a Murray Civil employee that a particular job was about to be changed and they should get there quickly and "f--king do a couple of trial holes and saw up the whole footpath ... then that'll stop that".

But Mr Cresnar denied he was trying to make work for Murray Civil, which won Ausgrid contracts worth more than $26 million between 2012 and 2013.

Mr Cresnar agreed Mr Twomey had given him a number of expensive gifts, including paying $7800 for an imported marble bath and marble toilets for his property in Alexandria in inner Sydney.

He denied the gifts were kickbacks and said he had given Mr Twomey "between 10 and 15" Royal Doulton-style jugs valued at up to $2000.

Earlier on Thursday, Mr Cresnar said that more than $70,000 in gifts from another contractor, Jason Bastow of Bastow Civil Constructions, were payment for "after hours" work he had done for Mr Bastow to help him formulate contract offers that were submitted to Ausgrid.

Bastow Civil won $20 million in Ausgrid contracts between 2007 and 2012. Mr Cresnar said he "didn't perceive any conflict of interest in secondary employment".

The former Ausgrid project engineer had said in a private interview with the commission last April that he did "nothing" in return for Mr Bastow "showering" him with gifts.

Asked to explain the radical change in his evidence, Mr Cresnar said:  "A few too many schooners between then and now."

"You are lying about that arrangement," counsel assisting the ICAC, Tim Gartelmann, said.

"How do you know I'm lying about it?" Mr Cresnar said.

Mr Bastow has given evidence that he felt he was being "held at ransom" by Mr Cresnar.

Mr Cresnar was employed as a graduate engineer by Ausgrid - one of the "poles and wires" electricity network companies the Baird government wants to privatise - in April 2006.

He resigned last year after the state-owned company served a notice of its intention to sack him.

Mr Cresnar said he had forgotten about another alleged gift from contractor Patrick Miskelly, whose company Fer-Aim secured more than $3 million in contracts with Ausgrid between 2010 and 2011.

He said the $2500 return airfare to Croatia was a thank you gift for helping Mr Miskelly with a patio and laying asphalt at his house.

Asked about more than $90,000 in cheques from another contractor, Eamon Burke, he said he saw the cheque book in the back of Mr Burke's truck and "assumed" that Mr Burke "was ok" with him spending his money for home renovations.

In a private interview last year, he said blank cheques from Mr Burke arrived in his letterbox.

The inquiry continues.