IPCA investigating cop's behaviour at out-of-control Christchurch party

The police watchdog is now investigating a policeman's actions at an out-of-control Christchurch party.

An officer was caught on camera calling a woman "skanky" before shoving another man to the ground, after he swore at him in response.

The incident was filmed as officers tried to quell a party of about 200 revellers at Ilam late Thursday night.

Canterbury District Commander Superintendent, John Price, said the incident has been investigated by Police Professional Conduct and handed over to the Independent Police Conduct Authority.

A man - who lived up the street and filmed the later altercation - said the "student" party had been going a few hours before it spilled on to the street.

Police began arriving and building up their numbers before forming into a line to sweep the partygoers out of the area.

That led to a number of arrests, the man, who did not want to be named, said.

However, the officer filmed in the video can be seen trailing behind his colleagues, who earlier moved up the street to arrest another person.

It was then a group of four people called out to the officer: "Hey, he's done nothing wrong".

An officer can be seen in a video shoving a man to the ground in an incident that was now the subject of a formal complaint. Photo / Supplied

The officer responds that he had warned the group to go home.

"Leave the area now or you will be arrested," he said.

The group say they haven't done anything wrong before one of the women says she will "tell my police officer father".

The officer asks "who's that", before starting to walk away while saying: "I'm sure he's really proud of having a skanky daughter in the streets swearing at the top of her head".

That prompted a man from within the group to say: "Don't f*** call my missus skanky".

The man can be seen standing still on the footpath.

But the police officer turns and walks fast towards him before shoving him hard in chest, flinging the man off his feet and on to the footpath.

The officer appears to point down and swear at the man.

"You were told to go home, now go home."

Climbing to his feet, the man responds "you're the man bro" to the officer.

The officer then walks away, saying "boohoo" to complaints from the group.

Police had received a formal complaint into the officer's actions and an investigation had commenced into what led to the incident and its filming.