NZ's first arrest of 2019 - and it was a particularly stupid one in Queenstown

Police say the man approached the sergeant from behind near The Mall and hit him in the head, knocking off his hat.

What a way to start the New Year.

A 19-year-old man from Timaru was arrested at 12.01am on January 1 for allegedly assaulting a police officer in Queenstown.

Police say the man approached the sergeant from behind near The Mall and hit him in the head, knocking off his hat.

He then attempted to run off with it.

"He didn't get very far,'' Senior Sergeant Paula Enoka, of Queenstown, said today.

"It's one of those things you just put down to too much alcohol. There's no other reason for doing something like that at midnight on New Year's Eve.''

The man was charged and due to appear in Queenstown District Court on January 7.

Police made five arrests in total on New Year's Eve and the early hours of New Year's Day.

Three were for assaults, including one in which an 18-year-old man allegedly broke a man's nose.

The other two arrests were for disorderly behaviour.

One of those, a 31-year-old man, was also charged with wilful damage after writing messages on police cell walls in his own blood.

He had been arrested in Frankton at 4pm and spent the night in the cells.

Snr Sgt Enoka said five arrests were "not too bad'' considering there were 100,000 extra people in the resort and an estimated 15,000 downtown celebrating on the night.

"There were people of all ages, families, youngsters, toddlers - many people were high-fiving officers as they walked past.

"But, overall, the levels of intoxication were still too high for our liking and there were people trying to get alcohol into the zone past the checkpoints.''

While there is a 24/7 liquor ban in most public places from December 27 to January 6 in the district, there were also checkpoints before people could enter the main party area near the waterfront.

Officers issued more than a dozen $250 infringements to people breaching the liquor ban.

"That's after a warning. They are refusing to pour away the alcohol.''

Police would continue working with partners and the Queenstown Lakes District Council to reduce drunkenness.

"Our focus is on people coming out, having a good time, and getting home safely. We don't want them to become a statistic.''