OUT OF CONTROL: Mr Whippy was not amused.

A chainsaw-wielding man wearing fishnet stockings chased a Mr Whippy van down the street after a stag party got out of hand.

The stunt failed to amuse Mr Whippy, who feared for his safety and phoned police.

Officers responding to the "quite bizarre" incident in Rangiora about 9pm on Saturday were able to easily identify the offender and arrested him for disorderly behaviour.

After interviewing him at the police station they decided to release him with a pre-charge warning.

"I fully understand the fears of the complainant," Sergeant Colin Stewart said.

"[But] it was a drunken antic. We used common sense and saw it as that."

Stewart said the man, who is in his 20s, had reportedly emerged from a White St property, revved the chainsaw into life and held it above his head as the ice-cream van went by.

"He was shaking it and waving it," he said.

Mr Whippy "wasn't travelling at great speed - probably within the 4kmh limit" so the man made chase along the footpath - still holding the running chainsaw.

He abandoned the chainsaw before leaping into the van's passenger seat.

Stewart said the man was polite. He said hello to the driver before alighting.

Police were provided with a description of the offender, namely a man wearing black fishnet stockings.

"It made him reasonably easy to identify," Stewart said.

When officers made inquiries at the property, the man "put his hand up to it".

"He was apologetic. It was more a disorderly behaviour thing than a direct threat [to the driver]."

Stewart said the offence was alcohol-fuelled at the end of an unusually hot day.