Yesterday Health Minister Tony Ryall, following Mr Thomson's refusal to resign from the chairmanship on Wednesday evening, wrote to board members advising he was considering removing Mr Thomson from the chairman's role over the $16.9 million fraud.
"Given the magnitude of the offending, and the loss of such a considerable sum of taxpayers' dollars, my confidence in the governance of the DHB and its leadership has been affected."
He was consulting Mr Thomson and the board, as required under the Public Health and Disability Act, and their views should be put to him in writing no later than 5pm on Thursday, February 5.
His final decision would be made once he had considered the points raised.
Mr Ryall said he was not considering removing Mr Thomson as a board member.
(Mr Thomson, while appointed to the chairman's role by the minister, is also an elected member of the board, possibly the only chairman in the country to be in such a position.)
While the legislation requires Mr Ryall to consult, there is no requirement for him to act in accordance with the views expressed during such a consultation.
A request for an interview with Mr Ryall was turned down by his office. Staff said it could be at least week before he commented further.
An attempt to seek comment from Prime Minister John Key about Mr Ryall's handling of the matter was also unsuccessful.
Board deputy chairwoman Susan Johnstone said last night it would be appropriate for board members to meet to discuss the issue, but she had not yet determined when that could be scheduled.
Mr Thomson said he thought Mr Ryall might have wanted to consult before "making such a song and dance", although perhaps he had thought by giving him the opportunity to resign it would avoid potential embarrassment.
About 20 messages of support were received by Mr Thomson yesterday and he had been gratified by the comments received, particularly those from board staff who expressed dismay.
Staff were left feeling "quite exposed".
Among the well-wishers was former Southland District Health Board chairman Dennis Cairns, who resigned at the end of last year. He told the Otago Daily Times Mr Thomson had done a fantastic job at the Otago board.
The pair had worked together over closer collaboration between Otago and Southland in their respective roles.
Former health minister Pete Hodgson accused Mr Ryall of following a partisan agenda, saying he seemed poised to act in defiance of the democratic outcome of the 2007 board elections.
Mr Ryall needed to remember that Mr Thomson had been the second-highest polling candidate, despite the alleged fraud being public knowledge.
All other board members seeking re-election were also successful.
At the time of that election, Mr Thomson had informed him he would not accept a ministerial appointment as chairman unless he was first elected by the public, Mr Hodgson said.