Three police officers have been rebuked for booze-fuelled behaviour after their colleagues expelled them from a Christchurch bar.

The off-duty officers were at a pre-Christmas function with workmates at the Pegasus Arms Restaurant and Bar on Friday, December 12.

On-duty police went to the bar about 7.30pm for liquor checks.

They believed their off-duty colleagues were intoxicated and told the group to leave the bar.

It is understood that, after leaving the bar, three off-duty officers took off their trousers and ran to the police station with road cones on their heads.

Canterbury District Commander Superintendent Gary Knowles said he was "aware of an alleged incident involving the behaviour of three off-duty staff who left a Christchurch bar on 12 December".

"The matter was investigated from an employment perspective and all of the staff involved have been spoken to," he said.

The police code of conduct required staff to "uphold the standards expected of them, regardless of whether they are on duty or not".

He took allegations of inappropriate police behaviour seriously.

"Any allegation that staff have not met these standards will be investigated thoroughly and appropriately," Knowles said.

Knowles was unaware of the specific details of the officers' behaviour, but said he welcomed further information.

Pegasus Arms business development manager Alex Brackstone said the bar took liquor laws seriously.

Six duty managers worked that night. Staff did not think the off-duty police were intoxicated, but supported the expulsion.

"From our perspective there were no issues, but we accepted their observation. They did think there were a few people becoming intoxicated. We took their advice and the people left the premises," Brackstone said.

"In lots of respects, police are probably harder on their own because they've got standards to uphold.

"We had no aggression, just a lot of happy Christmas cheer. If they [police] see something we haven't, it's brilliant and we support it."

"They [police] were just going around and doing their job, probably a bit more diligently and certainly earlier than usual," she said.