Prime Minister John Key has ordered an investigation into the NZ Security Intelligence Service's processes in granting top security clearance to disgraced former top defence scientist Stephen Wilce.

"The State Services Commissioner, Iain Rennie, has appointed Neil Walter, former Secretary of the Ministry of Foreign Affairs, to undertake this investigation", Mr Key said.

The investigation will cover the SIS's vetting processes used by the SIS with regard to Mr Wilce when he was hired in 2005 and the adequacy of the current vetting system.

The investigation would test the current regime to check it is "fit for purpose" and whether or not the system required strengthening.

The investigation is expected to be completed before the end of the month.

However, Green MP Keith Locke has called for a separate investigation to be headed by the Inspector-General of Intelligence and Security, Paul Neazor.

"The checks on Mr Wilce appear to have been inadequate, which is alarming for such a high security Defence position," said Mr Locke.

"I have asked the Inspector General, to investigate the vetting procedures in this case, because it might indicate a systemic failure within the SIS."

Mr Locke said such an inquiry should be conducted alongside others including that by the State Services commission announced today.

Mr Wilce resigned last week as head of the Defence Technology Agency after TV3's 60 Minutes program reported he had made false claims about his professional and sporting careers.

One claim made to 60 Minutes was that as a member of the British bobsleigh team in the late 1980s, he met the Jamaican team whose story was made into the film Cool Runnings.

However, Chris McCulloch contacted the Herald to say he was on the British Royal Marines/Royal Navy bobsleigh team with Mr Wilce at that time rather than the national team. However Mr McCulloch said the military team did in fact train alongside the Jamaican team at one time.

But Devon Harris, a member of the "Cool Runnings" team said although they did train alongside British teams at Innsbruck in Austria in late 1987, he did not recall Mr Wilce.

"If Stephen was in Austria at the time we would have undoubtedly met."