A source told NZME News Service the complainant believed there was "a pattern of behaviour that drove her to take a stand".
"She was fed up with what she and other staff had put up with over time."
The complainant had been made aware of other occasions where Mr Sutton's workplace conduct was called into question, it was alleged.
A second woman who worked closely with Mr Sutton corroborated the sexual harassment allegations and gave evidence to the inquiry led by State Services Commissioner Iain Rennie.
One insider said this week claimed that many women in senior roles at Cera would "have a tale to tell".
At Mr Sutton's tearful press conference on Monday, he apologised to the complainant. He added: "I may also have offended other women through my actions and I'm very sorry to them as well."
In his only interview since, on More FM with DJ friend Simon Barnett, Mr Sutton vehemently denied making lewd comments about John Key's wife, Bronagh.
He then refused any further interviews and asked that his family be given privacy.
Yesterday, he was photographed arriving at his hillside Christchurch home wearing a pink polo shirt, shorts and sandals.
"I'm just trying to act with some dignity," he said.
Meanwhile, other sources say there were problems with measures the commission put in place to keep Mr Sutton and the complainant at a distance while the allegations were being investigated.
These meant that he occasionally worked from Cera branch offices in the city, allowing the woman to work at the organisation's HSBC Tower headquarters. The arrangement meant the complainant was told where Mr Sutton would be, so the two could avoid running into each other.
However, NZME News Service has been told Mr Sutton allegedly didn't always stick to the arrangements and there were times the complainant believed they were both in the same building at the same time.
While their paths never crossed, the complainant raised concerns with the commission that Mr Sutton's actions meant it was a very real possibility, the source said.
"There were no controls and it wasn't strictly monitored. It wasn't an ideal situation," the source said.
The revelations again raise questions as to why Mr Sutton wasn't stood down by the commission while the complaint was being investigated.
Mr Rennie yesterday again refused to answer specific questions over his handling of the affair.
"Mr Sutton remained in his role while the investigation was carried out. Appropriate steps were taken to manage the situation while the investigation was taking place," Mr Rennie said.
State Services Minister Paula Bennett said yesterday she had been assured that appropriate steps were taken by the commission throughout the investigation.
But she said for the first time that she was not happy with how a press conference to announce the results of the investigation was handled.
"I have raised this with the State Services Commissioner and lessons have been taken on board to ensure there is not a repeat," Mrs Bennett said.
She continues to stand by Mr Rennie.
Labour's Christchurch Recovery spokeswoman Ruth Dyson said Ms Bennett had failed to "step up" this week.
"She should have said, 'This is turning into a nightmare for the complainant'. A proper process shouldn't turn out to be a one-sided slanging match through the media."
Ms Dyson said earlier this week that Mr Sutton had been "a real asset" to the city.
She said yesterday her comments specifically related to his contribution to the city's recovery and she knew nothing about the allegations against him.
Additional reporting, Isaac Davidson
