The Upper House parliamentary inquiry will hold a final hearing in Sydney on Thursday before tabling its report later in the day.
The final witness will be Riverina region councillor Shirlee Burge.
A high-profile list of requested witnesses avoided appearing at the inquiry including two of NSW Premier Dominic Perrottet's brothers.
Charles and Jean-Claude Perrottet were both summonsed to the inquiry which began in December following allegations senior Liberal party members were paid to install developer-friendly councillors onto the Hills Shire Council.
Committee chairwoman Sue Higginson singled out Liberal Councillor Virginia Ellis and her son Christian Ellis in particular for taking deliberate steps to avoid the inquiry.
"While some of these individuals have been engaging with the committee to some extent, all have been unable to be brought before this committee to be questioned," Ms Higginson said.
The Sydney property developer at the centre of the saga, Jean Nassif, also declined to give evidence to the inquiry which he was given the opportunity to do via videolink from Lebanon.
He has denied any wrongdoing.
Mr Nassif's 27-year-old daughter was arrested this week over allegations she dishonestly obtained $150 million from a falsified pre-sale contract.
Ashlyn Nassif faced court on Wednesday charged with two counts of dishonestly obtaining financial advantage by deception and publishing false and misleading material to obtain financial advantage.
She was released on bail under a $2.6 million surety.
The probe was launched after Liberal MP Ray Williams used parliamentary privilege in June to allege several senior party members had been paid to install councillors onto the Hills Shire Council to be friendly to Mr Nassif.
13°C