The initial pilot will be held in Norfolk, which has limited access to the helicopters flown by the National Police Air Service (NPAS) because they are based so far away.

If testing is successful, the devices would be stationed on buildings and operated remotely to be sent first to scenes to give police early information about the situation on the ground.

Trials are also planned by the Thames Valley and Hampshire forces.

Police have been working with law enforcement counterparts in the US, where drones as first responders (DFR) have been tried out in San Diego.

Belgium and the Netherlands are set to hold pilots.

Neil Sexton, who advises the National Police Chiefs' Council on the use of drones, said: "DFR is a drone that sits autonomously on a roof somewhere in a city, and it's in a box, it's protected.

"From a control station that receives a 999 call it can be launched completely remotely, flying overhead an incident to gain situational awareness that will be fed back not just to that control station or control room, but also to the first responders who are about to arrive on the ground."

The aim is the drone would give more accurate information on the potential scale of an incident than a potentially shocked member of the public who has called 999, and arrive at the scene much quicker than a helicopter.

Currently, police forces in England and Wales use about 400 drones that cannot be flown out of the operator's line of sight.

Plans are in place to change those rules to allow police operators to do so, with initial trials taking place in areas with closed-off airspace next year.

An increased role for drones is also being pushed for by police and crime commissioners.

Currently, all forces pay to fund the NPAS at a cost of more than £40m a year.

Earlier this week, chairwoman of the Association of Police and Crime Commissioners Donna Jones said helicopters could be "incredibly expensive" and drones are "much quicker" and "more agile".

"The technology now is improving incredibly, and police and crime commissioners have been pushing strongly to the Home Office that drones should be a very viable alternative," she added.

Forces are also proposing much wider use of retrospective facial recognition technology.

The biometric software, hailed as significant a step forward for policing as DNA analysis, is used to compare images from sources such as CCTV with force mugshot databases.

Britain's largest police force, the Met, has already said it will use the software to catch prolific shoplifters.

South Wales Police, one of the forces to pioneer use of live and retrospective facial recognition, is also piloting an app that allows officers to take a photo of a suspect and compare it to the force's computer records.

If the test is successful, the system could be rolled out across England and Wales.