Revelations about the appointment of former NSW deputy premier John Barilaro to a taxpayer-funded trade job in New York City have become a "huge scandal", Labor says.
An upper house inquiry examining how Mr Barilaro landed the role as the state's senior trade and investment commissioner to the Americas has already found evidence of political interference and shown a public servant lost her job in the process, Opposition Leader Chris Minns says.
"Through their efforts we've determined that far from this being an independent process, it's been politically interfered with," Mr Minns told reporters on Thursday.
The inquiry heard on Monday that former public servant Jenny West was initially offered the role in August last year before it was given to Mr Barilaro last month.
Mr Barilaro has since withdrawn from the position amid public scrutiny and insists proper processes were followed.
"We've also discovered that (Ms West's) substantive role in the NSW public service was yanked from her after she was denied the New York position," Mr Minns said.
"Obviously, this is a huge scandal, and it'll be interesting to see what the NSW government's response is.
"I still haven't heard any convincing reason why the eminently qualified Jenny West was sacked from her position and John Barilaro was placed into it."
The inquiry, formed in mid-June, heard from Investment NSW chief executive Amy Brown last month and from Ms West on Monday.
Portions of Ms West's testimony were sent to the state's Independent Commission Against Corruption.
Deputy Premier Paul Toole said on Wednesday it was important the inquiry was able to investigate the appointment.
"We need to ensure that the inquiry process runs its due course. I'm not going to pre-empt the outcome of what that inquiry might be," Mr Toole told reporters.
He said he didn't have conversations with Mr Barilaro about the appointment.
Ms West, a former deputy secretary for Investment NSW, told the inquiry that after being offered the role by Ms Brown and given a briefing signed by then-premier Gladys Berejiklian, her offer was rescinded.
She said Ms Brown later told her the job would be a "present for someone".
Ms West was made redundant from her role at Investment NSW in November.
Her testimony conflicted with statements made by Ms Brown, who told the inquiry she withdrew the offer after the relationship between Ms West and the government became "irreconcilable".
Two staffers who worked for Mr Barilaro will give evidence to the inquiry on Monday, along with Department of Enterprise, Trade and Investment general counsel Chris Carr.
