Police Commissioner Howard Broad says there's no need to hold an inquiry into the use of police informants in some activist organisations.
He met Police Minister Judith Collins on Monday. She sought reassurance that informants are not being misused.
A Christchurch man, Rob Gilchrist, is accused of passing information about people involved in activist organisations to the police for a decade.
Mr Broad says the police do follow-up on people they believe pose some risk to the public, and may include members of groups such as Greenpeace.
But he told Nine to Noon that such organisations are not targetted directly.
Mr Broad said he's seeking further details about the use of informants in this case, but has seen no sign that breaches of privacy have occurred.
Opposition leader Phil Goff says the special investigation unit was set up to deal with external threats to New Zealand. It was given extra funding in 2004 when he was the Minister of Foreign Affairs.
Mr Goff says he would not expect it to be involved in spying on a legitimate protest group.