UPDATED 11.58AM: Two-thirds of doctors treating terminally ill patients have made decisions that may have hastened their death, a new survey finds.

The Auckland University survey shows 65.6 percent of doctors admit to withholding or giving drugs to end a life.

Of the 650 doctors who were asked about the last death they attended, more than 16 percent withheld treatments and 4.5 percent administered a drug to hasten death.

LISTEN TO AN INTERVIEW WITH AUCKLAND UNIVERSITY'S GLYNN OWENS ABOVE

This backs an earlier survey this month by the GP's Association.

Study author Dr Phillipa Malpas hopes the survey will entice more discussion around the topic of assisted death:

"It seems to me that we do need to have this discussion in society about what's happening at the end of life," Malpas said. "What do people want, the kinds of discussions that they're having with their families, [and] the kinds of discussions they're having with health professionals."

Malpas said in a 2004 study nurses and doctors were evenly distributed and the reasons for their actions were varied.

"It may be that death was forseen but certainly not intended," she said. "And it may be that in fact that many of the nurses were alleged to be involved saw what they were doing as good palliative care."

Eighty percent of patients were judged to be within the last week of their life.

Psychology Professor Glynn Owens, of Auckland University, commends the doctors who opened up and took part.

"With good careful precautions for confidentiality people were willing to tell us. I think it shows how important some people are thinking this issue is."

Owens believes open discussion is the only way forward on the debate of assisted suicide.

Meanwhile, the Health Select Committee has formally agreed to investigate whether the public would support legislation allowing voluntary euthanasia.

Former MP Maryan Street, whose petition sparked the review, believes it will reveal a majority view in favour of such a provision.

"There will be a lot of very intense and emotional submissions, I don't doubt, and those that oppose it will oppose it vociferously."

"The chair [Simon O'Connor] has said that he wanted a robust process and a robust outcome and I'm very pleased about that."

Street insists people will recognise that the weight of public opinion is in favour of a protective law.