The Herald requested details of the settlement, including any payout, under the Official Information Act.
The request was declined six days later.
In its response, a CDHB spokesperson said: "Dr Alistair Humphrey has resigned from the Canterbury DHB and any details surrounding his resignation are private and confidential.
"We are therefore declining your request pursuant to the following sections of the Official Information Act."
Humphrey had been employed by the CDHB since 2000 and was a Medical Officer of Health (MOH) for most of that time.
Employment relationship breakdown
Humphrey was allegedly dismissed last year after CDHB executive Peter Bramley concluded his employment relationship with the health board was "irremediably untenable", resulting in an "irretrievable breakdown".
CDHB submissions filed for the reinstatement hearing alleged a part of the breakdown in Humphrey's relationship with the health board was due to him not accepting he was accountable to his line manager and his interpersonal relationships with his co-workers.
The submission alleged co-workers described Humphrey as displaying "combative and belittling behaviour" and described discussions at meetings as "strained and apprehensive".
At the reinstatement hearing, Humphrey's lawyer Carolyn Heaton argued the longer he was away from his position and no longer practising, the more difficult it would be for him to get back into the industry.
She also argued it was likely to permanently damage his career.
Heaton told the hearing that Humphrey was not distrusting of his colleagues or unable to follow direction but was unhappy he was not being notified of problems as they arose.
Judge Christina Inglis, in the Employment Court decision to temporarily reinstate Humphrey, said he had a clearly arguable case for permanent reinstatement and the potential impact on his colleagues by interim reinstatement could be managed.
Humphrey dropped a personal grievance against the Canterbury District Health Board that was set down for a hearing this month.
"Having served the Canterbury District Health Board well for twenty years, Dr Humphrey has now resigned to engage with other professional opportunities," a spokesperson for Humphrey said in a statement last month.
"He wishes his former colleagues in Community and Public Health all the best for the future."
It has been reported that Alistair Humphrey has since taken a new role as chair of the New Zealand Medical Association.
