The dogs were found in a police car parked outside Nottinghamshire’s force headquarters in Arnold at 2.15pm on Wednesday, when outside temperatures reached 29.4C.
The RSPCA are investigating the incident and the officer, who was on duty at the time, could be charged with causing unnecessary suffering to an animal, which carries a fine of £20,000 and or a six month prison sentence.
The Independent Police Complaints Commission said it was also deciding whether to investigate.
A spokesman for the RSPCA said: “Nottinghamshire police called us within minutes of the incident and we are investigating. We will be making contact with the officer and investigating this as much as we can. It is a very serious incident.”
It takes 13 weeks of intensive training and costs more than £9,100 before a police dog can go out on patrol. Nottinghamshire Police said the handler has not been suspended. It is not known how long the dogs had been left in the car or if there was any ventilation. Many of police cars have what is known as a “run lock” that allows the engine and air conditioning to run while keeping the doors locked.
Peter Davies, the force’s assistant chief constable, said: “This is a tragic incident and we value the important work our police dogs carry out on a daily basis.
“That is why we swiftly reported this incident to the RSPCA and we will be working with them very closely.”
A statement from Nottinghamshire Police added that the welfare of its animals was “of paramount importance”.