The police unit that protects the Prime Minister and other VIPs has had another budget blowout - this time by almost $1.3 million.
The police had a budget of just under $5 million in the financial year to June 2013 but spent more than $6.2 million. It is the fourth year in a row the budget has been blown by the diplomatic protection squad.
Inspector Phil Jones, the officer in charge of the squad, said it was difficult to forecast accurately the budget because of the nature of their work.
But part of the overspending has been blamed on a system introduced to reduce time off in lieu accrued by staff while on protection duties.
"A new, more efficient roster and deployment system was implemented during the 2012-13 year ... To assist in the introduction of the new system, the existing time off in lieu balances which had been accrued over the previous years were paid out to DPS staff," Mr Jones said.
Superintendent Barry Taylor, national manager of operations, said after the time off in lieu buy-back, the squad had underspent for the year.
"Police is constantly prioritising its resources according to operational requirements and the difference has been met from within existing operating budgets without impacting on other services," Mr Taylor said.
Police Minister Anne Tolley said police were responsible to her for living within their total allocated budget and they were doing that.
"The DPS perform an important function in protecting dignitaries, and the Police Commissioner is responsible for its operational management. I trust police to deploy DPS officers as they see fit, and politicians cannot and should not interfere in any of these decisions."
After previous budget blowouts, Opposition parties accused the Prime Minister of being partly responsible for the increased spending because of what they claimed was an overuse of security details, even within Parliament.
Labour police spokeswoman Jacinda Ardern told the Herald Mr Key's use of the DPS was unprecedented. "Even from what we have observed within Parliament, there seems to be an increase in staff."
Ms Ardern said former prime ministers did not rely on so much security and it was up to Mr Key to justify it.
"We're sort of working in the dark because we don't really know what sort of threats or reasons there could be [for the increase]."
A spokeswoman for Mr Key said he had nothing to do with the decisions police made on security.
"The Prime Minister considers his protection staff to be extremely hard-working professionals," the spokeswoman said.
DPS officers are based in Auckland and Wellington and provide VIP protection for the Prime Minister, Governor-General, guests of the Government and embassies and consulates.