He said in the letter the board had undertaken an extensive search for a CEO to replace Craig Climo including in New Zealand, Australia, Canada, the United Kingdom and the United States.
"We received 28 formal applications and among those Dr Murray was clearly the stand out candidate."
Simcock said extensive discussions with people who worked with and for Murray in Canada, at Southland DHB where he was chief in 2007 and at Auckland DHB, where Murray was deputy chief executive before that, were glowing.
"We believe he has the experience and ability to take advantage of the significant capital investment our board has made over recent years, and to lift the performance of our district health board to one of leadership in the New Zealand health system."
He wrote the letter two days after Murray was announced the front runner for the job, on June 6, which was the same date Murray resigned his post in Canada.
Murray reportedly wanted to return to New Zealand for family reasons – his elderly father who lives in the Waikato was apparently ill.
His resignation came after a damning BC Government-ordered review showed Fraser Health Authority was the worst performing in Canada, in part due to budget shortfalls.
Its interim board chairman at the time, Wynne Powell, told the Herald this month it took 12 months to turn Fraser Health around.
On June 12, 2014 the Association of Salaried Medical Specialists, the union for senior doctors, warned the DHB in a press release that Murray was not suitable for the job.
Executive director Ian Powell said the DHB appeared to be rushing into hiring someone who had a "polarising leadership style".
The same week Simcock wrote to the SSC former Labour MP Sue Moroney met with him to issue a similar warning and said she was given a personal undertaking by Simcock he would "keep an eye on Murray".
On June 16, 2014 the SSC replied to Simcock advising that practice services executive manager Hannah Brownsey consented, under delegation, to the proposal to appoint Murray as chief executive.
The total salary was redacted but she noted the "appointment at this level of remuneration may limit Dr Murray's annual remuneration increases in the future".
But Murray, who was reported in the Vancouver Sun in November 2008 as not being "in it for the money", received a six-figure salary increase at Waikato DHB the next year.
The Herald reported in December last year that Murray's total remuneration went from between $440,000 to $450,000, to between $560,000 to $570,000 in the DHB's 2015/16 Annual Report.
Waikato DHB spokeswoman Lydia Aydon said then the extra money was a mixture of performance pay, cashed-out annual leave and KiwiSaver contributions.
The article raised the ire of Simcock who wrote a lengthy response published in the Herald pointing out Murray only received a 2 per cent pay rise that year, that the previous year's earnings were short three weeks because Murray didn't work the full year, and that some of the performance pay was carried over from the year before.
An SSC investigation into Murray's $218,000 expenses during his three years at Waikato DHB, along with Simcock's oversight of the spending, is expected early in the New Year after Murray quit in October amid an expenses scandal.
Simcock quit on November 28. The Herald has revealed that the Serious Fraud Office was making preliminary inquiries into the case. The Auditor-General is also making inquiries.
A Waikato DHB spokeswoman said the DHB could not comment because the arrangement was between Simcock and Murray.
Meanwhile the Otago Daily Times reported that Murray claimed credit in his resume for the Southland and Otago DHB merger, even though he wasn't there when it went ahead in 2010.
