West Midlands Police said the aircraft, which was parked at Elmdon Airport in Birmingham, suffered "extensive damage" in the blaze.

Assistant Chief Constable Gary Cann said: "At about 2am this morning, the air traffic control service called the fire service, who attended Elmdon Airport, which is where the helicopter is stored, and found that the aircraft was on fire."

He added: "We do suspect that it is an arson attack, which is why we have launched a criminal investigation immediately."

Forensic experts and detectives were at the scene and are working closely with airport security staff and West Midlands Fire Service.

Mr Cann added: "While the investigation is ongoing, we would like to reassure the public that we will continue to provide air support when necessary."