POLICE and border control authorities are to use an unmanned aircraft to patrol the south coast to catch illegal immigrants trying to enter Britain by boat.

The aircraft, already used by British forces in Iraq and Afghanistan, will take still pictures as well as video footage of boats suspected of being used for smuggling people and beam them back to police control rooms.

It is understood the police have expressed interest in using the £5m drone to monitor crowds during demonstrations and events such as football matches.

Although the British-built aircraft, called the High Endurance Rapid Technology Insertion (Herti), will fly above 20,000ft, its cameras are powerful enough to see humans on boats as if they were a few feet away. It will also be capable of taking pictures in darkness using night vision lenses.

The Herti is being adapted by BAE Systems for the South Coast Partnership, a security project which involves the Border and Immigration Agency (BIA), Kent police and Essex police.

The Herti was once one of BAE’s classified “black” projects, whose existence was unacknowledged. Early models were reportedly tested in the Australian outback to minimise the chances of them being seen.

The new project was announced by BAE at a police aviation conference in the Hague last month. Andrew Mellors, head of civil autonomous systems at BAE, told the conference: “From 2012 fully autonomous unmanned air systems could be routinely used by border agencies, the police and government bodies.”

The Herti has a wingspan of over 41ft, is more than 16ft long and almost 6ft high. It can fly for 25 hours at a stretch, relaying live images back to its control room. The drone can be sent on preprogrammed routes or commanded directly by the click of a mouse on a laptop. It can be controlled from more than 600 miles away and can fly at 140mph.

On-board sensors also give the drone the ability to deal with unexpected incidents, for example by automatically changing course to avoid coming close to other planes in the crowded airspace.

BAE Systems is in talks with the authorities to ensure that the drone does not interfere with civil or military flying. It said that the Herti, in addition to its sensors, had transponders to allow other aircraft and ground controllers to see it on their radar.

A spokesman for the BIA confirmed that it was exploring the possibility of using the Herti, but said that it had not yet made a decision.

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