The member for Drummoyne appeared as a witness at the NSW Independent Commission Against Corruption inquiry for the first time on Tuesday, saying he signed whatever his parents put in front of him.

The four-week ICAC inquiry is airing allegations Mr Sidoti improperly influenced people in their exercise of their official duties between 2011 and 2018 in relation to the rezoning and development of land at Five Dock in Sydney's inner-west.

The inquiry will also examine whether he breached public trust by failing to make a number of pecuniary interest disclosures contrary to his obligations.

The corruption watchdog on Tuesday heard the MP, who now sits on the cross bench, had worked for his parents managing the front of house operations of a Sydney function centre they bought in 1992.

In 2007, his parents sold the business and transferred ownership of the property to the Deveme Pty Limited Staff Superannuation Fund.

Mr Sidoti, his wife Sandra and his parents were made trustees of the Deveme Super Fund in 2000, meaning the property was sold "inside the family circle", ICAC counsel assisting Rob Ranken said.

"Technically they've sold it from themselves to themselves. That was my understanding," Mr Sidoti said.

The Deveme Super Fund is also the trustee to the Sidoti Family Trust, of which Mr Sidoti, his wife and children are beneficiaries.

Mr Sidoti did not declare his financial interest in the property - 120 Great North Road at Five Dock - or his roles as trustee as required as part of his roles in parliament.

The property forms part of a development application advanced by Mr Sidoti and a group of friends, which the counsel assisting argues the MP sought to improperly influence councillors over.

ICAC previously heard Mr Sidoti engaged town planners to lobby council into rezoning the area to allow for more development on the sites owned by his family and friends.

But Mr Sidoti told the inquiry he had no knowledge he was a trustee of the family business, and therefore had a financial interest in the property, until the allegations were raised in parliament in 2017.

That's despite Mr Sidoti admitting he signed documents in his capacity as a trustee, including a sale contract and a form consenting to his appointment to the position.

"I'm not sure what I've signed to be honest with you," he said.

"I worked for my parents and ... you know, you sign that, sign this, sign that.

"I'd sign on request because I've been signing the same sorts of documents from 1992 when I was 22 years old.

"I was just thought it was my role as a son, as an employee."

Mr Sidoti has previously said he "absolutely rejects the allegations" of impropriety and had always acted with integrity and honour.

The former sports minister resigned from the NSW government cabinet in March.

He then also withdrew from the Liberal partyroom, citing the allegations as a distraction for his colleagues.

The inquiry continues.

Australian Associated Press