Future: Britain's skies could be filled with devices such as the Pentagon's 'nano-hummingbird'
The skies could soon be filled with the buzzing of thousands of tiny spy drones trained to snoop on British streets, the Home Office has warned.

They are one of a number of futuristic snooping techniques that could become reality including CCTV that recognises faces and cameras in the back of taxis.

The warning comes as the Pentagon revealed it is pumping hundreds of millions of dollars into new drone technology such as the 'nano-hummingbird' - a tiny remote helicopter equipped with video and audio equipment that can record sights and sounds.

Ministers said that advances in technology have meant such hi-tech measures are now possible and could soon be ubiquitous across the country.

The suggestions came in a proposed code of practice drawn up to help regulate the spread of CCTV, that will be overseen by a newly appointed Security Camera Commissioner.

The consultation document, revealed by the Daily Telegraph, stated that traditional CCTV was of 'limited value' to police because images are often too grainy to identify suspects or badly placed.

It said: 'Modern digital technology is on the cusp of revolutionising the use of CCTV.

Buzzing: The Nano Hummingbird is tiny remote helicopter equipped with video and audio equipment that can record sights and sounds
The consultation said powerful zoom features, 360-degree vision and facial recognition 'are coming closer to being an established part of the CCTV landscape'.

It continued: 'New uses for systems, for example in taxis, are a natural part of industry growth.'

And of the possibility of launching unmanned drones into the sky, it said: 'There is scope for their unchecked proliferation and attendant risks if they are not considered within any overarching strategy.'

Under the proposed code, police and councils will have to explain exactly why they want to place a camera in a certain place.

Information Commissioner Christopher Graham last year blasted Britain for becoming a surveillance state where snooping techniques were advancing so quickly that regulators were unable to keep up.
Big Brother: Britain is already one of the most watched countries in the world with one CCTV camera for every 14 people

But the Home Office's most recent paper will only bolster fears that Britain is turning into a Big Brother state, despite the Coalition Government vowing to clamp down on the expansion of snooping techniques and restore civil liberties.

Britain is one of the most watched countries in the world with one CCTV camera for every 14 people.

But despite this, police admit that just one crime is solved for every 1,000 cameras.

Campaign group Big Brother Watch director Daniel Hamilton praised the paper as a 'step in the right direction'.

He told the Daily Telegraph: 'For far too long, the police have been able to operate with impunity, scarcely giving any consideration for personal privacy.

'Today's warning serves as a real shot across the bows. People want to see more officers on the beat, not costly gimmicks like clip-on cameras and spy drones.'

The U.S. government has announced plans to develop tiny drones and large unmanned aerial systems for its armed forces.

Many are inspired by nature and are designed to look like birds, so they blend seamlessly into the sky, such as the nano-hummingbird by California-based technology firm AeroVironment.

But there are larger models too, such as the 'Global Observer', an unmanned aircraft that can fly continuously for up to a week at an altitude of up to 65,000ft and can reach any point on the globe within hours of take-off.

They claim they could be used by the military to spy, but also to find people trapped inside buildings destroyed by a major earthquake, like the one most recently that devastated the New Zealand city of Christchurch.