NSW Police have launched an investigation after the death of two police dogs on a training exercise in Sydney’s south.

Police Dog Xtra and Development Dog Soldier were found dead in their air-conditioned pod in a police vehicle at Lucas Heights just after midday on Thursday.

They were taken to a specialist veterinary clinic but were unable to be revived.

“The air-conditioner cools the pod on the rear of vehicles. So it is modified for that exact reason. It is top-of-the-range stuff that was introduced back in 2023,” NSW Police transport and public safety commander Assistant Commissioner Stephen Hegarty said on Friday.

“We have really good equipment. We don’t understand why that’s taken place.”

Temperatures in southern Sydney reached the high 20s on Thursday. Temperatures inside a closed vehicle can be much higher than outside.

Police would not comment on whether heat was a factor in the sad incident.

Hegarty said the dogs’ handler was at a lecture 300 metres away. Shortly after midday, he went to check on them and found the vehicle’s motor had cut out – which also meant the air-conditioning stopped working.

“The dogs can be in the rear of a car at night time for long periods of time. So it is not unusual and nowhere near against any processes or training that we’ve given the officers,” he said.

Detectives attached to Sutherland Police Area Command and Fleet Services are leading an investigation into the circumstances surrounding the incident.

Xtra was a German shepherd attached to the Newcastle/Central Coast Dog Unit who had been a police dog since July 2018.

Soldier, another German shepherd, was a younger dog who began police service last February.

Commissioner Karen Webb said the handler was devastated by the incident.

“He had the very difficult task of going home yesterday afternoon to inform his wife and his two children about the passing of the two dogs because the two dogs … reside with the family,” she said.

“They are part of that family [and are]with the officer 24/7.”

The police vehicle was being examined for any mechanical, technical or engineering problem that led to the tragic circumstances, Webb said.

“There’s no suggestion that this is human error,” she said.

She said both dogs were highly trained and played a vital role in assisting officers in serving the community.

“Today is a very sad day for the dog unit and the thoughts of the whole police family are with them,” she said.

“We owe it to PD Xtra and DD Soldier to conduct a thorough investigation.”

Hegarty said the loss would be felt deeply by the command.

“Our focus is on the welfare of all staff involved with ongoing support services made available to them,” he said.