Britain's most senior police officer has said he is "very saddened" by the deaths of two police dogs left locked in a hot car.
Sir Paul Stephenson said Scotland Yard was taking the matter "very seriously" and carrying out an internal disciplinary inquiry alongside the RSPCA investigation.
A police dog handler being investigated over the deaths threw himself from a colleague's vehicle after the incident.
Sergeant Ian Craven, 49, flung himself from the car and was then declared a missing person, a source confirmed. The officer was later found in Newham, east London, with hand injuries.
Sir Paul, the Metropolitan Police Commissioner, said: "I'm very saddened by what's happened and we are taking it very seriously. There's an investigation going on. It's being led by the RSPCA, with a separate internal disciplinary investigation going on in the force."
Sgt Craven left two dogs, a working Belgian Malinois and a German Shepherd puppy, in an unventilated car at the Met's dog training centre in Keston, Kent, on Sunday. He went to a meeting off-site and called colleagues to alert them when he realised the animals were trapped.
The Directorate of Professional Standards has launched an investigation into the deaths, which occurred as temperatures soared to as high as 29C in the South East.
