The Minister of Police is demanding answers after the Police admitted they lost confidential papers which got into the hands of the Mongrel Mob.
The documents were left behind during a police raid on a house in the suburb of Pomare, Lower Hutt, as part of an eviction process by Housing New Zealand against five gang members.
On Tuesday, another Government agency, Housing New Zealand, admitted it "mistakenly" included a complainant's contact details and those of an employee in eviction notices sent to the gang.
Police say the information in the documents does not compromise the safety or security of any individual.
The Dominion Post reports it was a police manual containing confidential call signs and the names and ranks of officers as well as the contact details of a complainant about the Mob.
Lower Hutt Police say the document contained information about which officers were carrying firearms in the raid.
Inspector Geoff Gwyn told Morning Report the document detailed which officers were carrying weapons, the type of weapons and where they were being deployed to.
He maintained that no individual officers' security was compromised.
He says the officer who left the report behind will be dealt with internally.
Incident to be raised with Commissioner
Police Minister Judith Collins says she will raise the incident with Commissioner Howard Broad.
Labour says it's unacceptable that two Government agencies made serious blunders in their handling of the same case. Leader Phil Goff says the situation is unbelieveable.