The ambulance crew was attending an emergency in Newcastle

The vehicle's crew were treating a patient in the Walker area of Newcastle, when the remote controller for its satellite guidance system was taken.

Regional ambulance bosses described the theft as "despicable" and have ordered a review of security procedures.

It could mean paramedics on their way to an emergency having to stop and lock the doors of vehicles after parking, potentially wasting vital life-saving moments.

A spokesman for Northumbria Police said the theft happened between 0507 GMT and 0525 GMT on 3 January.

When crews are trying to get to a patient's address it helps them get there faster and could make the difference between life and death Paul Liversidge, North-East Ambulance Services

The doors to the ambulance had been left unlocked as staff treated a patient inside a house in Baret Road.

Paul Liversidge, director of accident and emergency services for the North-East Ambulance Services, appealed for witnesses to come forward.

He said: "It is despicable to think that someone has stolen this vital equipment from an emergency ambulance.

"The equipment is very important. When crews are trying to get to a patient's address it helps them get there faster and could make the difference between life and death."

The navigation system uses satellite technology to guide ambulance crews to a particular address and cannot be used without the remote control device.

It is relied on when staff are called out to areas outside the vicinity of their own station and are not familiar with the street lay-out.