NSW upper house MPs have engaged professional help to track down two of the premier's brothers, who are wanted to appear before an inquiry into allegations of impropriety at a Sydney council.
Jean-Claude Perrottet and Charles Perrottet are among four people who have been summoned to give evidence but have, so far, evaded parliamentary staff tasked with serving them.
The parliamentary inquiry is examining allegations of impropriety of the Hills Shire Council and property developers in the area.
Committee chairwoman, Greens MP Sue Higginson, has urged those sought by the inquiry "to do the right thing and come forward".
"I can only reach the conclusion that they are making a deliberate decision to avoid appearing before the committee," she said.
"We will now step up our efforts to secure the attendance of these individuals at a public hearing, including by engaging professional process servers to serve the summonses."
The committee has acknowledged Charles Perrottet may not be currently in the state.
Charles and Jean-Claude Perrottet are both factional figures of the Liberal Party in the Hills area.
When asked on Tuesday, Premier Dominic Perrottet said he had not spoken to his brothers.
"Let's be very clear, this is Labor and the Greens playing politics a month out from the election," he said.
The inquiry was launched after Liberal MP for Castle Hill Ray Williams alleged members of the NSW Liberal Party had been "paid significant funds" to install new councillors in the Hills area to benefit the development company Toplace.
Mr Williams made the allegations under parliamentary privilege in June, and the inquiry was called six months later.
Developer mocks 'political kabuki', blasts public release of letter
Property developer Jean Nassif, the director of Toplace, has also been called upon to appear before the inquiry.
He is currently in rural Lebanon, he says "recuperating from a medical procedure before travelling further" for business reasons.
Last week he wrote a letter to the inquiry, which was released publicly, denying the allegations made by Mr Williams.
He has now written a second letter, which is critical of the committee for releasing the letter and revealing his whereabouts because "it is inherently dangerous due to my particular circumstances".
Mr Nassif also raised concerns about the media coverage of his failure to appear before the inquiry and the motivations of the inquiry.
"The suggestion that I have left to avoid the inquiry is as ridiculous and counter-factual as Mr Williams's allegations," he said.
"You are participating in political kabuki and I am happy to participate."
He says upon legal advice, he will not be appearing at the inquiry via video link.
"If you can provide with me any logical explanation for why you waited six months to call this inquiry, then I will make special efforts to fly immediately to Australia and be before you in person," he said.
"However, I am sure you cannot."
The inquiry will hold public hearings over the next two days.
Former Hills Shire mayor Michelle Byrne is set to appear.
