Extra police resource called to Whanganui in the wake of the shooting of Kevin Ratana in August last year cost more than $80,000 in the first two weeks.
Ratana, a father of two and patched Mongrel Mob member, was shot at his home in Puriri St on August 21.
Extra police officers, along with the police Eagle helicopter, were brought into Whanganui as part of the investigation as fears of a gang retaliation escalated with the arrival of about 100 Mongrel Mob members from out of town for Ratana's tangi.
Initial requests to the police for information on costs were declined under section 6(c) of the Official Information Act which allows information to be withheld if it would likely prejudice the maintenance of the law, including the prevention, investigation and detection of offences, and the right to a fair trial.
However, the Chronicle lodged a complaint with the Ombudsman in October and police have since agreed to release some information.
"As at December 4 2018, police had recorded total costs of approximately $83,000 attributable to the investigation for the period up to September 4, 2018 [the date of the request]," Sergeant Gary Ferguson of Central District Police said.
The amount mainly related to the costs of accommodation, travel and meals associated with extra staff brought into Whanganui. Police did not keep data of the staffing costs of a particular investigation.
Police did not have complete data about the costs.
The cost of using the Eagle helicopter was not included. Ferguson said its use was not always recorded against a particular investigation and was not in this case.
Ferguson said police believed the information had been properly withheld (at the time) but "due to the passage of time, police consider they can now release some information related to costings".
The figure was "likely incomplete as recording costs against an investigation is not the primary financial accountability mechanism for police", he said.
It did not separate a "prevention phase" and "operation phase" of the investigation.
Seven men, all members of Black Power, have been charged with Ratana's murder and are next due to appear in court in September.