A statement from Bond said: “During normal operations yesterday, one of our EC135 fleet has experienced an indication defect that requires further technical investigation.

“Therefore as a precautionary measure we have temporarily suspended service operations whilst we undertake detailed diagnosis. We commenced investigations overnight, are continuing this morning and are in close liaison with Eurocopter regarding this investigation.”

The police helicopter that crashed into a bar in Glasgow on 29th November, killing ten people, was a Bond-operated Eurocopter EC135 Type 2 aircraft.

West Midlands Ambulance Service spokesman said: “Clearly safety is our number one priority and will be guided by the operator of the aircraft.

“As a service we still have access to two air ambulances; those operated by Warwickshire and Northampton Air Ambulance and Derbyshire, Leicestershire and Rutland Air Ambulance so we have no concerns about patients being put at risk by this situation.

“In addition, the crews that would have been flying today will respond on land vehicles as they would if the weather had stopped the helicopters flying. We are hoping for an update later today on when the situation is likely to be resolved.”