The spotlight has shifted to whether ACC Minister Judith Collins had any role in the decision to set police on to whistleblower Bronwyn Pullar, as bloodletting continues at the troubled corporation.

Chief executive Ralph Stewart quit his $600,000-a-year job yesterday – following chairman John Judge, deputy John McCliskie, board member Rob Campbell and Cabinet minister Nick Smith as casualties.

Mr Stewart and Mr Judge faced criticism over their decision to lay a complaint with police against Ms Pullar, after it was alleged she had tried to blackmail ACC managers.

Police said they investigated and Ms Pullar had not committed any offence.

Now questions are being asked what involvement Ms Collins had in the move to go to police.

She insists the decision was made by the board alone.

But asked if she ever expressed the view that they should go to police, she said: "Well, I don't recall that I ever have. What I can say is that that decision was theirs, and it was always theirs and I supported them. I don't think they could have done anything else.

"Whatever the discussions were it was very much on the basis that they had to make their own decisions. They were briefing me about what they knew."

Ms Collins said she was briefed by Mr Stewart and Mr Judge and asked them to prepare a written report after The Dominion Post revealed ACC had inadvertently emailed Ms Pullar the names and details of thousands of clients.

"The first I've got a record of receiving that they were getting assistance from police or certainly referring the matter was in that report I got."

Green MP Kevin Hague asked Ms Collins to give a "categorical assurance" to Parliament that "she neither instructed nor approved nor suggested that ACC make a complaint to the police concerning Bronwyn Pullar."

She replied: "My comments to the chair and the chief executive were that they must make their own decision. It is not for me to be involved in those individual decisions."

Labour MP Andrew Little called for Ms Collins to be sacked. Going to the police was "the wrong thing to do".

"Replacing them [Mr Stewart and Mr Judge] alone is not going to change things. They did what their political masters told them what to do, so actually the political master has to change."

Ms Collins, currently engaged in a defamation battle with Mr Little and MP Trevor Mallard, fired back: "It actually has to stop, this silly nonsense."

Mr Hague believes she should keep her job. The "sick entitlement culture" in the corporation is the "big picture issue".

"She's clearly said ACC's privacy settings are unacceptable and must change and that's actually a pretty good start. She may be the minister to do all this."

However, he said questions remain over the Pullar saga.

"If she has acted improperly ... then she's got to be answerable for that."

Former Axa boss Mr Stewart said the events of recent days "has brought me to the point where I have decided to step down as CEO".

It was "an incredibly hard decision to take".

Ms Collins had sympathy with Mr Stewart. "He's had a tough time," she said.

Mr Campbell confirmed he was not reappointed, adding: "No reason was given or discussion had with the minister."

The embattled state insurer has hired two PR firms – paying them $269,325 since October.

It emerged Acumen Republic was hired to carry out polling.

A senior partner from Senate SHJ was installed in the Wellington head office as the crisis deepened.

- © Fairfax NZ News