Department of Customer Service secretary Emma Hogan told budget estimates on Wednesday she first became aware of issues in the office of former fair trading minister Eleni Petinos in April, after she was promoted to cabinet in December.
They were not formal complaints but Ms Hogan says she raised some issues with the minister.
"One was concerns about respectful behaviour in meetings and others about some cultural concerns that had been raised with me about working in her office," Ms Hogan said.
Premier Dominic Perrottet sacked Ms Petinos from cabinet on July 31 after an anonymous complaint by a staffer alleging bullying.
Customer Service Minister Victor Dominello, who took over Ms Petinos' portfolio, says he never received any formal or informal complaints about bullying in her office.
He was aware of some "workflow issues", he told the hearing.
"Ms Petinos was a new minister, I know what it's like to be a new minister.
"It's hard yards and it takes some time to get your feet underneath the table," Mr Dominello said.
Mr Perrottet initially defended Ms Petinos when bullying allegations emerged from her office but she was ousted from cabinet after he spoke to Ms Hogan.
A July 7 resignation letter from NSW Building Commissioner David Chandler noting a problematic relationship with Ms Petinos and concerns he had over a property group she had met with twice the month before, was sent to the premier's chief of staff by Ms Hogan hours before Ms Petinos was sacked.
The premier said he did not read the letter before sacking Ms Petinos or before it was sent to the Independent Commission Against Corruption the next day.
The issues were raised peripherally by Ms Hogan, who said they had been appropriately dealt with, however the meeting and sacking were about Ms Petinos' workplace behaviour, the premier said.
Ms Petinos ordered a review of whether Mr Chandler had misled parliament when he said it was not his role to recommend certifiers, after a video of him telling builders he had given banks an "informal list of certifiers" he would not use was reported by The Australian in June.
Ms Hogan told Wednesday's hearing the nature of the industry he policed meant "various attempts" had been made to "interrupt" the commissioner but no such list actually existed and he had not lied to parliament.
"Mr Chandler had perhaps been a little more elaborate than he should have been on a building site … but I saw that no further action needed to be taken," she said.
Mr Chandler withdrew his resignation last month.
Mr Dominello who is not contesting the March election, welcomed Mr Chandler's decision to stay.
"We need a strong commissioner here that is going to shine a light on, quite frankly, some appalling developers that need to be held to account," he said.
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