Senator Arthur Sinodinos continues to be embroiled in the investigation over political donations to the NSW Liberal Party, and his latest efforts to defend his position have been rebuffed by the NSW Election Commission.

Last week the commission announced it was withholding $4.4 million in public funding to the NSW Liberals until the party disclosed who donated a sum of $693,000 before the 2011 state election.

The move prompted the senator to write a letter of complaint to the commission, saying he had not been afforded “procedural fairness” or “basic decency” by not being warned of the commission’s announcement.

Sinodinos said that errors in the commission’s statement had a potentially damaging effect.

“It appears on transcripts of ICAC selectively used to make a particular point, without the opportunity for people like me who are affected to make their part of the case,” he said.

On Thursday the commission hit back, saying it refused to retract any statements it has made on the matter.

The withholding of the $693,000 donation relates to a fund-raising campaign for the New South Wales 2011 election campaign when Sinodinos was the NSW Liberal Party treasurer.

The senator has consistently denied any knowledge of wrongdoing in relation to funds raised during his tenure as treasurer, a position he held while also being the non-executive chairman of Australian Water Holdings, which made a $30,000 donation to the Liberal war chest as it battled insolvency.

At the heart of assertions against Sinodinos is whether he was aware of the donation at the time, and the implications of a potential conflict of interest over his role as an AWH company director and NSW Liberal Party finance director.

The Independent Commission Against Corruption (ICAC) inquiry into the matter (that began in 2014) and took evidence from the senator is yet to be finalised, but reports suggest Sinodinos will not face corruption findings.