Simcock was solely responsible for authorising Murray's expenses which amounted to a comparatively high $108,000 for the first two financial years in the job from July 2014.
In an open letter to Simcock, board member Dave Macpherson said he had concerns about the processes "and your role in them, relating to the control of and approval for the CEO's expenses..."
Macpherson said Simcock should have known Murray did not disclose his first expenses by August 2015 and taken action then.
"A second annual CEO expenses return was required to be filed in August 2016 but was not."
He claimed Simcock did not check the expenses when they were finally disclosed in January 2017, after the Herald revealed Murray was under fire by the State Services Commission for not filing them.
"Irregularities in these reports could have been found and addressed nine months ago, had you fulfilled what I believe is your obligation to be on top of the CEO's expenses, on behalf of the board."
He said the lack of action then had put the board and possibly the whole DHB in jeopardy.
Board member Mary Anne Gill said she was not aware of any vote of confidence by the board in Simcock but noted she and Macpherson left the special board meeting last Thursday, when members discussed Murray's future, because of conflicts of interest.
She would not say if she had confidence or not in Simcock because she was awaiting the outcome of the audit.
"The investigation is ongoing so it's something that we as a board need to discuss once we have all the information."
She also questioned whether the previous board, of which she was not a member, knew Murray's expenses for the first two years were not filed on time.
Simcock first raised the issue with Minister of Health Jonathan Coleman in June this year but it was five weeks before he alerted the board to the situation and an investigation was launched.
However it's understood concerns were first raised by staff last year over Murray's spending.
Murray also spent $140,000 in an 18 month period while head of Fraser Health Authority in Canada, immediately prior to returning to New Zealand to take up the $560,000 a year post at Waikato DHB.
Waikato deputy chair Sally Webb said she had full confidence in Simcock and "every indication was that the vast majority" of board members at Thursday's special meeting also did.
Both she and board member Sally Christie would not say whether a vote was taken during the meeting.
Christie echoed the sentiment that she had absolute confidence in Simcock, along with board member Pippa Mahood.
"With regards to the process that happened with Nigel I think Bob did an excellent job," Mahood said.
"He followed process to the letter and it was a difficult time and I certainly support what he did... He hasn't done anything that I have seen that would make me feel otherwise."
Board member Crystal Beavis supported Simcock's "broad leadership" including his role in improving governance and restructuring committees to include more of the community.
She said the board was satisfied with his role in checking out Murray's references and feedback on him prior to his appointment. He also kept the board informed of the steps he was taking to manage the issue since the end of 2016.
"It would be fair to say we all assumed the issue would be dealt with properly by our chief executive."
Beavis was still waiting for the outcome of the audit into its processes, but referred to Thursday's board statement which said there had been "other unauthorised" spending.
Meanwhile a petition calling for a vote of no confidence in Simcock was launched yesterday by a Hamilton resident and is being hosted on the New Zealand Taxpayers' Union website.
