A number of frones have been spotted over US bases in Britain(Image: East Anglia News Service)

Mystery drones over UK 'proof of Vladimir Putin's covert agents probing the West'

Colonel Hamish de Bretton-Gordon, the former head of the British Army's chemical weapons unit, claimed the mystery drones may be part of a Kremlin plan to 'test the waters'

by · The Mirror

Mysterious drones seen flying over US and UK military bases in recent weeks may be Russian “sleeper agents” used to "test the waters", a defence chief has warned.

The devices have sparked major speculation and concern over who sent them and why, with authorities yet to make any progress in tracking down the source. Several have pointed the finger at Russia, including experts who believe Putin may be carrying out an intelligence-gathering mission referred to as "ferreting", to threaten and test rival airspace defence plans and response times.

Colonel Hamish de Bretton-Gordon, the former head of the British Army's chemical weapons unit, claimed the mystery drones may be part of a Kremlin plan to "test the waters" and expose weaknesses in the defences of British and American bases, MailOnline reports.

He added Putin may have activated sleeper agents to run the operations, with dozens of reported drone sightings across New Jersey, the East Coast and now over US bases in Britain.

Drones in the US were said to be as big as cars( Image: ABC)

US Congress members have called for a state of emergency to be declared amid reported sightings of drone clusters in the night skies across the east coast in recent weeks.

One Republican representative hinted at the possibility the drones were deployed "by violent dictatorships, perhaps maybe Russia, or China, or Iran, or North Korea.” The FBI, White House and Pentagon have meanwhile stressed that none of the activity poses a credible threat.

Mystery drones have also been spotted around the UK, with Brits left stunned after seeing a suspected drone flying close to an American air base in Britain. A suspected drone could be seen flying over Hockwold cum Wilton, just six miles from the RAF Lakenheath base, in Suffolk - which will soon become the home for some US nuclear weapons.

Col de Bretton-Gordon believes sleeper agents are using drones to record Britain's response times, troop numbers and kit to prepare them for future attacks on bases abroad.

Colonel Hamish de Bretton-Gordon says the drones may trying to expose weaknesses in British defences( Image: Martin Bagott)

He warned: "It’s no secret that there are sleepers and stuff around. It’s espionage 2.0. It’s the next stage. So, this is absolutely the case. If you're a young person and somebody is giving you several thousand dollars to do something that seems dead straightforward, you will do it."

He added that a similar "toe-dipping" tactic was being used when Syrian dictator Bashar al-Assad used chemical weapons in 2013. Col de Bretton-Gordon said: "The Assad regime was really testing the water. He did two sarin nerve agent attacks and nothing happened, despite the fact I went to the area and investigated and bought samples back to the UK and warned ministers of it.

"Assad and his henchmen were testing the water and suddenly realised the West was interested and they then went full on. I’m sure that’s exactly what it is that's happening now in the US and UK... They are testing to see where the weaknesses and vulnerabilities are."

Defence sources in the UK say there is “no evidence” that the drones soaring over US air bases in the UK were linked to Russia, China or Iran. But former British UFO hunter Nick Pope said he could not “rule out” the recent incursions being connected to Russia and China.