FRESH questions about the extent of British complicity in US drone strikes and other so-called targeted killing missions have been raised following the leaking of documents about a top secret North Yorkshire spy base by whistleblower Edward Snowden.

Campaigners who have spent decades pressing for the closure of RAF Menwith Hill, between the Yorkshire Dales and Harrogate, said the details contained in the US National Security Agency (NSA) papers had given an unprecedented overview of the base’s activities.

The Northern Echo: An aerial shot of RAF Menwith Hill

SPYING: An aerial shot of RAF Menwith Hill, in North Yorkshire

A US-based investigation has claimed the files reveal how the NSA has used the eavesdropping technology at the British base – where more than 2,000 personnel are based, most of whom are American – to assist in “a significant number of capture-kill operations” across the Middle East and North Africa.

The documents are said to have revealed the base, which is visible across a wide area of the county due its giant white domes which contain powerful antennae, can gather data from more than 300 million emails and phone calls a day.

It has been claimed the base has spying facilities titled Overhead and Fornsat which monitor communications between foreign satellites and wireless communications.

Investigators claimed the papers reveal over the past decade the base has pioneered spying programs, with names such as Ghosthunter, at Menwith Hill to locate terrorism suspects using the internet in remote places, information from which has been used for British and American military operations in Iraq and Afghanistan.

The programs are also said to have aided covert missions in countries where the US has not declared war, including a mission to help “eliminate” terrorism targets in Yemen, where US drone bombs have killed dozens of civilians.

The documents are said to show that in 2007 analysts at Menwith Hill helped track down an al Qaida-linked suspect called Abu Sumayah in Lebanon who was described as “highly actionable” and was traced to within a few hundred metres from intercepted communications. It is claimed a document shows the details were passed to a special operations unit known as Task Force 11-9.

Menwith Hill campaigner Lindis Percy said while the RAF and Ministry of Defence police did not appear to know what was going on at Menwith Hill, the files appeared to show they were protecting illegal activities.

She said: “It is horrific. We knew something of what they do at Menwith Hill, but didn’t know the extent. A case needs to be brought to court.”

An MOD spokesman said: ‘The MOD can confirm that RAF Memwith Hill is part of a worldwide US Defence communications network, with the base supporting a variety of communications activity.”