Investment NSW managing director Kylie Bell appeared before a parliamentary committee inquiry on Friday, two days after the scandal claimed the scalp of former trade minister Stuart Ayres.

Meanwhile, another member of the selection panel told the inquiry if there was more transparency over the recruitment process she would never have endorsed him for the job.

Ms Bell said the recruitment process was imperfect, but she was never contacted by any government office seeking to appoint Mr Barilaro.

She endorsed Mr Barilaro's candidacy "based on his skills and experience with this very particular role".

Documents revealed at the inquiry show a report from specialised recruitment firm NGS Global grading candidates was altered to give Mr Barilaro a higher rating.

Ms Bell said the firm revised the report as it did not reflect the views of the selection panel that had assessed candidates.

"I feel like there was a bit of an unconscious bias against (Mr Barilaro) if I'm honest," Ms Bell told the hearing.

She said wording in the report was amended, expanding Mr Barilaro's attributes, but denied Hong Kong-based executive Kimberley Cole was "downgraded".

"All we did was include in the text why eventually she had not been selected on the comparison to Mr Barilaro," Ms Bell said.

"The question became whether she was going to be great for this particular role, given most of her expertise was in Asia," Ms Bell said.

She suggested Ms Cole was considered favourably by the recruiter because it knew Investment NSW had no women senior trade and investment commissioners.

NSW Public Service Commissioner Kathrina Lo, who sat on the selection panel, said she lost confidence in the hiring process following the inquiry's revelations.

"Had I known on 15th June what I know now, I would not have endorsed the report," Ms Lo told the inquiry.

The level of ministerial involvement including shortlisting of candidates, the seeking of informal references, and engaging with the candidates, led her to her conclusion.

She added she had never seen a draft version of the report which ranked Ms Cole above Mr Barilaro.

Mr Barilaro signed his contract a day after she signed the report.

Another panel member, former Liberal MP Warwick Smith, also formed the view he would not have signed off on Mr Barilaro, she said.

Ms Lo said evidence previously given at the inquiry made her concerned her role as public service commissioner could make her a target over the appointment.

"I'm a participant on the panel. I don't have elevated status compared to any other panel member," Ms Lo said.

"I should not be viewed as cover for a recruitment process, or as a way for other panel members, or the high hiring agency, to avoid accountability."

Earlier, Mr Barilaro's former chief of staff Siobhan Hamblin told the hearing she could not recall any urgent requests to change the trade commissioner roles to ministerial rather than public service appointments.

Ms Hamblin said she had been pre-occupied with COVID-19 at the time, as NSW was in lockdown.

"Given that I can't recall that, I suspect that whatever the answer was didn't raise with me any particular red flags," she said.

Labor committee member Daniel Mookhey suggested the urgency might be because Mr Barilaro had already started considering his resignation.

"That's a question for Mr Barilaro," Ms Hamblin said.

The former deputy premier's much-anticipated appearance at the inquiry is scheduled for Monday.

Secretary of Investment NSW Amy Brown will also appear for the third time.

Labor has pledged to abolish all senior trade and investment commissioner roles if it wins the March state election.

Opposition trade spokesman Anoulack Chanthivong said the roles had been "mired in scandal" and a suitable replacement program would be developed.

Australian Associated Press