The Police Association says alcohol lobby groups are having undue influence on local councils to force bars to stay open later.
Questions are being asked about a possible deal being struck between the Wellington City Council and the hospitality industry over bar closing hours which have been set an hour later than the rest of the country.
Radio New Zealand News has obtained emails from court records about a June meeting between council officers and Hospitality New Zealand, where it was agreed that bars could remain open until 5am.
The law requires all bars to close at 4am, unless their local council allows them to close later.
The change in Wellington City Council's draft alcohol plan to close at 5am is being appealed to the Alcohol and Regulatory Licensing Authority by police and local health authorities.
Police Association president Greg O'Connor said the meetings between the alcohol lobby and the council demonstrated the kind of pressure police predicted when the law was changed two years ago.
"What we said at the time - [it] was predicted that local councils would come under considerable pressure by lobby groups, particularly the hospitality industry, to keep the bars open and again, that's what's happening."
Wellington mayor Celia Wade-Brown has denied a deal was hammered out before the draft alcohol plan went to public submissions.
Hospitality New Zealand's Wellington branch president Jeremy Smith said the meetings were held but were not meant to decide the final policy - but bars said they could live with a 5am closing.
"I said I could live with 5am, but that didn't mean that was what the policy was going to be, that was just one organisation saying 5am is something we could live with, we're not happy with it, but we understand that we need to be part of the solution."