British military bases face a drone epidemic – raising fears of spies from Russia and China.
Craft have made it into airspace around Ministry of Defence sites more than 150 times in just three years.
Data uncovered by the Sunday People found sightings at some of the UK’s most secretive and sensitive bases.
Ex-Afghanistan commander Colonel Richard Kemp said: “Many incidents might be harmless but it would be naive to believe some are not efforts to gain information and probe security by foreign intelligence services such as Russian and Chinese.
"The drone is an increasingly valuable weapon for governments as well as terrorist groups.”
The sightings were reported to MoD Police, Britain’s only fully armed force responsible for guarding the chemical weapons lab at Porton Down and GCHQ spy centre in Cheltenham.
Drones capable of flying hundreds of metres high and avoiding detection can be purchased for less than £500.
Freedom of Information requests show the number of incidents involving bases has risen from eight in 2014 to 79 last year.
Some experts suggest thousands of Russian spies are active in the UK.
Dr Andrew Foxall, an espionage expert at the Henry Jackson Society think-tank, said up to half of the 150,000 Russian expats in Britain may be “assets”.
And intelligence sources have said some of the drone attacks were “almost certainly” conducted by foreign spies.
Former British Army head General Sir Mark Carleton-Smith warned Russia “indisputably” poses a greater threat to Britain than ISIS or al-Qaeda.
An MoD spokesman said: “We employ a range of security measures to counter all conceivable threats.”
