The police are investigating claims by a former undercover officer that he lied in dozens of court cases.
Patrick O'Brien was the subject of a 2008 investigation by senior lawyer Bruce Squire after he claimed he had committed perjury and taken drugs during an undercover stint in the 1970s.
Mr Squire says he completed the report several months ago and gave it to the police.
Waitemata Detective Inspector Bruce Scott says he has now been asked to investigate the case by staff at Police National Headquarters.
He says his job is to look at whether there was any criminality to Mr O'Brien's behaviour.
Mr Scott says he has made contact with Mr O'Brien by email but has yet to interview him.