An ex-Labor staffer picked to lead the NSW transport agency personally donated to the re-election campaign of the responsible minister before his controversial appointment.
The revelation comes as Premier Chris Minns admits the recruitment process for transport secretary Josh Murray's appointment wasted taxpayer money as it wasn't needed.
The government has come under fire since appointing Mr Murray to the key post in July, with critics pointing to it as an example of "jobs for the boys" under the Labor administration.
Transport Minister Jo Haylen's office requested Mr Murray be interviewed after recruiters declined to shortlist him and a $125,000 process was run to assure the minister he was the best candidate for the role.
Documents tabled in parliament showed Mr Murray made a personal donation of $500 to Ms Haylen's political campaign before Labor won government.
The information was included in a series of talking points about the appointment from Ms Haylen's office under a question about whether Mr Murray had made any contributions to her campaign.
"Yes, but they were of a non-declarable value," read the suggested response.
As well as Mr Murray's $500 donation in September 2022, the documents revealed a related party, whose name was redacted, also donated $250 in October that year.
A spokesperson for Ms Haylen said the minister has "answered questions in relation to declarations that need to be made".
"She has no private interests in this matter," the spokesperson told AAP in a statement.
Mr Minns earlier on Monday admitted that the $125,000 outlay on the recruitment process was, in hindsight, unnecessary.
"Given that Mr Murray was appointed to the job, obviously, we want to make sure that we don't spend that money when we don't need to," he told Sydney radio 2GB.
"In retrospect, it wasn't required.
"If you know who you want for the position, we want to make sure that we're in a position where we can appoint those senior public servants for those difficult jobs."
Opposition transport spokesperson Natalie Ward said Mr Murray's donation to Ms Haylen's campaign raised "serious questions about the conduct and management of the appointment".
Ms Ward urged the government to release any documents that could confirm conflicts of interests were declared and managed.
"By any objective measure the interests of donor to a political campaign of politician is a personal interest and a conflict, which requires appropriate declarations," she said in a statement.
The government has previously dismissed suggestions of wrongdoing and argued that Transport for NSW's $26 billion annual budget is far from a cushy role, unlike in other recent "jobs for the boys" scandals.
Mr Murray was a chief of staff in the Iemma Labor government before working in corporate affairs at infrastructure giant Laing O'Rourke.