"I don't think it is terribly likely that the Government would be advancing it," Mr Key said of the proposal contained in a leaked document.
"It is probably not new news that some people think there should be a restructure of health governance.
"[But] history tells you reorganisation of the health system...takes quite a long period of time. Just from the anecdotal feedback I've had from the [Health] Minister I don't think it's something they are actively looking to progress."
A leaked document out of the office of new Director-General of Health Chai Chua includes a proposal to remove the control of DHBs from elected representatives.
Currently most of the country's 20 DHBs have 11 members, of which seven are elected at local government elections.
The proposed changes outlined in the document would reduce the number of board members to nine, with six being appointed by the health minister.
DHBs are governing bodies responsible for overseeing the delivery of health and disability services in their districts.
Health Minister Dr Jonathan Coleman told Radio New Zealand that he had not read the third party report, which had been "stolen" and released to media.
"I'd have to consider it in a wider context, but changes to DHB governance are not top of my list - I think it's pretty unlikely...this is a long way from being government policy."
Labour's health spokeswoman Annette King said those comments were not believable, particularly as the document had been seen by DHB chief executives and chairs.
The leaked document clearly showed the Government planned to "take a scalpel" to democratically elected health boards, Ms King said.
"The proposed restructure includes centralising control, replacing elected board members with a razor gang of Government appointed ones, and disbanding both the National Health Board and the National Health Committee.
"Alongside that, the Director General will be involved in setting performance pay for chief executives while four new pools of funding will be created, imposing extra levels of bureaucracy."
By Nicholas Jones of the New Zealand Herald
