A senior police officer has condemned colleagues for using their cellphones while driving, saying it is a joke to go out and enforce the law when officers appear to be readily flouting it.

Another officer has been caught on camera talking on his cellphone at traffic lights. He was filmed by a motorist in West Auckland on Thursday.

"I wound down the window and started recording, I was yelling out trying to get his attention," said the motorist, who did not want to be identified. "Then the light turned green and he casually drove off, still talking."

The motorist sent the footage to the Herald after seeing a similar photograph in Friday's paper showing a man believed to be an officer talking on his cellphone on the Southwestern Motorway.

Staff at police national headquarters were not convinced the man was an officer and said that, either way, there were provisions in the law allowing officers to talk on their cellphones if it was within the execution of their duties.

But several senior officers, one with 25 years' experience, said there was no doubt it was one of their colleagues.

The senior officer said it was unacceptable for police to be using cellphones while driving unless it was a real emergency. "I'm out there telling people off for using their phones while they drive. And yet cops are out there doing it. I am absolutely pissed off by the hypocrisy," he said.

"That is definitely a police officer."

Another top-level officer had no doubt the Holden the man was driving was a police car. It had steel wheel-rims rather than alloy - a specification generally found only on the police fleet as it was cheaper.

The Herald was inundated with emails from readers over the weekend who had spotted officers using their cellphones while driving.

"I actually reported a policeman in a marked police car driving on St Lukes Rd talking on the mobile phone, driving around 65km/h and changing lanes without indicating," said one.

Another reader concerned about a female officer using her phone on the harbour bridge was disappointed with the response to his official complaint. He was quoted the relevant act.

He said the car's occupants were highly animated and he doubted the the conversation was police-related.

The Land Transport (Road User) Amendment Act 2009 states: an enforcement officer may, while driving a vehicle, use a mobile phone to make, receive, or terminate a telephone call if ... in the execution of the officer's duty.