John Barilaro has challenged an inquiry probing his appointment to a plum taxpayer-funded US trade role, claiming it failed to produce any evidence of misconduct and vindicated him as the best man for the job.

A defiant Mr Barilaro questioned the committee probing his appointment to the $500,000-a-year trade role in New York over whether it had uncovered anything that challenged the integrity of the hiring process.

During one heated exchange with committee chair Cate Faehrmann, the former deputy premier asked: “What did I do wrong?”

Controversy over Mr Barilaro’s appointment to the coveted job has engulfed the Perrottet government since it was announced in June, claiming the scalp of minister Stuart Ayres after a draft review suggested he might have intervened in the hiring process.

“There’s no evidence in this hearing that points to me that I did seek, sought, pressured, public servants in any way. None. Zero,” Mr Barilaro said Monday.

“If anything you have heard from apolitical public servants … who said that I was capable, and a credible candidate, that I would be good at the job.

“They’re the ones who offered me the job.

“What did I do wrong? I got offered a job, I accepted the job.”

However, the former Nationals leader says he now regrets applying for the role, which he resigned from two weeks after his appointment was announced in June.

“If I knew what I know now, I wouldn’t have walked into what was a s**tshow,” he said.

He said the past seven weeks had been significantly traumatic, and no colleagues warned him applying could cause political issues, despite consulting Treasurer Matt Kean, Mr Ayres and the premier about his ambitions.

He said many people had offered their support.

Mr Barilaro did agree other candidates would not have had the same access to the premier or ministers as he did.

He also addressed claims from his ex-chief of staff Mark Connell, who told the inquiry Mr Barilaro wanted the New York job in 2019.

The former MP called Mr Connell’s account false and fictitious, and questioned details in his account, including whether certain meetings had occurred.

He also denied knowing public servant Jenny West had been the successful candidate ten months before his appointment, saying a document confirming her selection only contained his digital signature.

He said he may have directed staff to sign the document for him.

Mr Barilaro also told the inquiry former premier Barry O’Farrell was one of three high-profile referees on his job application, along with Department of Regional NSW secretary Gary Barnes and Ambassador to the United States Arthur Sinodinos.

The former Nationals leader said Mr O’Farrell had been a big supporter of his for more than a decade.

“He is a dear friend and I sent him a message and he offered to be my referee, it is as simple as that,” he told the inquiry on Monday.

Labor’s Daniel Mookhey put to Mr Barilaro his prominent referees could have been “a key factor” in him getting the role.

Mr Barilaro rejected that.

Mr O’Farrell, now Australia’s high commissioner to India, resigned as NSW premier in 2014 after it was revealed he misled the Independent Commission Against Corruption, when he denied receiving a $3000 bottle of Grange Hermitage wine.

Mr Barilaro told the hearing Premier Dominic Perrottet also supported his bid for the role after he flagged his interest in November, one month after announcing his intention to resign from politics.

“He was just like, ‘great’, and that was it,” Mr Barilaro said.

Mr Barilaro will give evidence again on Friday.

When asked about the recruitment process on Monday, the premier said he would implement recommendations from the independent review his government launched in June.

“It’s clearly come to light there were issues in relation to the recruitment process,” Mr Perrottet told 2GB radio.