Two men accused of murdering an undercover police officer last September were today committed to stand trial in the High Court at Auckland.

John Ward Skinner, 37, and Iain Lindsay Clegg, 35, are both charged with murdering Sergeant Don Wilkinson during a night-time police surveillance operation.

They are also charged with attempting to murder another police officer, who has name suppression.

Skinner faces a further count of assault with a weapon against a third officer, who also has name suppression.

Skinner and Clegg were committed to trial after a three-day depositions hearing in Manukau District Court.

They will appear in the High Court on April 29, when a trial date was expected to be set.

Today a police officer told the Manukau District Court he heard three quick shots then groaning and gurgling during a night-time surveillance operation in which his colleague was shot dead.

The public were excluded, the doors locked and the windows covered to protect the officer's identity while he gave evidence. His name suppression continues.

Nobody was allowed to enter or leave the court room while he was giving evidence.

Mr Wilkinson died at the scene, while his partner survived being shot three times.

They were taking part in an operation to plant a tracking device on a car in the suburb of Mangere in the early hours of September 11.

The officer told Crown prosecutor Aaron Perkins under questioning that he was wearing a stab resistant vest.

The officer told the court he was with two other officers that day. They had positioned themselves outside a property in Hain Avenue, along the fence line in the shadows.

Mr Wilkinson moved towards the front of the property, which set off a sensor light. Then more lights came on the courtyard.

Both officers started running, and the officer giving evidence said he thought he heard a voice at the front door step.

They ran off the property and headed towards Earlsworth Avenue, and the officer told the court he heard Mr Wilkinson call on his radio that they were at their car.

"We heard a loud V8 car starting up, and it started speeding up. We ducked down a driveway, and the car passed us. It reversed and came back towards the driveway.

"I was on the radio at this stage calling for back-up.

"The driver got out of the car and started coming towards me. I had a bag which I put down and moved two or three paces in front, approaching the driver with my hands up in front of my body," the officer told the court.

He said the driver approached him and said "What do you think you are doing?"

The officer said he tried to talk his way out of it, as he knew back-up would be coming very soon.

Another man (Skinner) appeared from behind the driver (Clegg). The man was holding a rifle and aiming it at the officer.

"The rifle was being pointed at my chest. I turned my head to the left, and I felt a blow to the side of my head. The force was enough to break my nose and cut through my eyebrow.

"I threw my hand up and I was shot through the forearm.

"I fell to the ground and I was shot again in my back.

"I then heard three quick shots at Sgt Wilkinson and a lot of groaning coming from behind me," the officer said.

Mr Perkins asked the officer if he got any response from Mr Wilkinson, to which he replied "no".

Under cross examination by Clegg's lawyer, Stuart Grieve, QC, the officer told the court both officers were wearing dark clothing and rolled up balaclavas.