The Russian jets flew just 4.5 meters from the British plane before launching a missile (Photo: Getty Images)

An RAF aircraft allegedly came chillingly close to being shot down by Russians over the Black Sea last year, intelligence documents show.

An RAF RC-135 Rivet Joint surveillance aircraft, also known as a “nuke sniffer”, was flying near Russian-occupied Crimea when a squadron of Su-27 fighters was just 15 feet away.

One of them fired “a missile in the vicinity” of the British spy plane, Defense Secretary Ben Wallace said at the time.

But leaked US military documents claim that September’s missile launch nearly hit the RAF aircraft.

A Russian Su-27 nearly shot down the British plane in September

The alarming incident happened in September

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They describe it as a “near shot on UK RJ (riveted joint)”, MailOnline reports.

The incident could have dragged the UK and its NATO allies straight into the war in Ukraine.

The Kremlin blamed a technical error and Mr Wallace agreed to accept this explanation and drew a line under the incident.

A British defense source has argued that the US documents are false, telling MailOnline: “These reports contain inaccuracies and do not reflect what happened in international airspace over the Black Sea.”

The RAF regularly flies over the Black Sea to gather intelligence.

The role of the Rivet Joint aircraft is to suck up electronic transmissions and communications.

Since the incident, RAF surveillance aircraft have been escorted by Typhoon fighters – while the US has opted to deploy unmanned drones.

Pentagon spokesman Brigadier General Patrick Ryder has stressed that it is vital that the Black Sea and the airspace above remain open to all nations.

Royal Air Force Boeing RC-135W Rivet Joint military reconnaissance aircraft taking off from RAF Mildenhall Air Base.;  Shutterstock ID 1151994743;  Command: -;  Function: -;  Client: -;  other: -

An RAF RC-135 Rivet Joint spy planeknown as “nuclear sniffers”, gathered information about the Black Sea Shutterstock / VanderWolf Images

“The Black Sea is an important international sea route that supports many of our NATO allies, including Romania, Bulgaria and Turkey, and is not owned by any country,” he said last month.

His comments came after a Russian fighter jet accidentally crashed into a US drone.

This prompted the US and Russia to make efforts to recover the debris, with Russian ships sighted at the crash site on 15 March.

The Pentagon insisted that the parts could not be recovered and that all information had been erased.