The government has been asked to investigate whether BT is aiding drone strikes with a specially built military internet cable connecting US air force facilities in Northamptonshire to a base for unmanned craft in Djibouti on the Horn of Africa.
Evidence is mounting that the $23m (£13m) fibre-optic circuit built by BT in 2012 was installed to facilitate air strikes in Yemen and Somalia by US air force drones, according to a complaint filed by the human rights group Reprieve.
The circuit runs from RAF Croughton, a base where US air force personnel staff a command, control, communications and computer support hub for global operations organised by the US military.
Its ultimate destination is Camp Lemonnier in the small republic of Djibouti. A former French Foreign Legion outpost refitted in a $1.4bn project commissioned in 2012, Camp Lemonnier is where the Pentagon has established the most important base for drone operations outside Afghanistan.
The circuit BT built can carry live video images, transporting digital information at the rate of 2.5 gigabits per second, about 30 times faster than BT's superfast home broadband service Infinity, which advertises 80 megabits per second.
The contract asked for the cable to be operational by 12 October 2012, and runs until 14 October 2017. The circuit appears to connect Djibouti not only to the UK, but also to Capodichino near Naples in Italy, where the US navy has its European and African command centres. The circuit can use terrestrial fibre-optic or undersea cables, but the contract states that it must avoid India, Pakistan, Iran or Syria.
This year, in Yemen alone, up to eight confirmed drone attacks have killed an estimated 71 people, including a child, according to data gathered by the Bureau of Investigative Journalism. The bureau believes there have been as many as 60 confirmed drone attacks in Yemen since 2012, with 385 killed, including 47 civilians and five children.
Reprieve, which is acting on behalf of two Yemeni men whose relatives were accidentally killed by drones, told the Guardian that it has brought a new complaint against BT, filed with the British government on 19 August.
The group filed a first grievance against BT in July 2013, with the UK National Contact Point (UK NCP) for the Organisation for Economic Co-operation and Development. The UK NCP team is within the Department for Business, Innovation and Skills.
An initial assessment was carried out, but the complaint was rejected in February this year.
The NCP decided there was no evidence to "show a specific link between the communications service provided and the impacts of drone operations". BT described the Lemonnier cable as a standard circuit for general communications purposes, and said it had not been made aware of its exact uses.
Since then, Reprieve said new evidence had emerged from a technical analysis of the firm's contract with the US government that reinforces suspicions the cable has been used in the operation and surveillance gathering of American drones.
The analysis comes from a series of investigations published by the specialist magazine Computer Weekly, which shows that BT's Camp Lemonnier cable was part of the US military's Defence Information Systems Network (DISN).
Reprieve quotes a recent US defence department paper which specified that "drones rely on DISN connections for global distribution of mission data and for long-range command & control functions".
The campaign group says day-to-day communications at Lemonnier are supplied via a contract with a local company, Djibouti Teleco.
The BT contract also states that information passing through the circuit is to be protected by KG-340 devices, which use algorithms specified by the NSA to encode information classified as top secret.
Reprieve claimed: "BT's cable likely supports the round-the-clock drone strikes in Yemen and Somalia operated by the United States air force and Central Intelligence Agency as part of its "targeted killing" programme. Without a declared war, these drone strikes are used in an opaque and secretive manner without any supervision or accountability, a clear violation of international law."
It is not known whether drones launched in Camp Lemonnier are piloted from the UK, although they can be piloted from as far away as the United States.
BT said in a statement: "UK NCP assessed Reprieve's complaint in February and rejected it. BT can categorically state that the communications system mentioned in Reprieve's complaint is a general purpose fibre-optic system. It has not been specifically designed or adapted by BT for military purposes, including drone strikes. We have no knowledge, beyond press reports, of US drone strikes. We take our human rights obligations very seriously and are fully supportive of the OECD guidelines."
The UK is a signatory to OECD guidelines, which protect human rights, the environment and consumer interests. The role of the UK NCP is to ensure corporations and public agencies follow the guidelines, and to carry out investigations into whether they have been breached.
Reprieve accuses BT of "wilful ignorance" about the use its cable is being put to. It is now calling on the former government-owned telecoms company to cease providing services under its five-year contract with the US government, or amend it so that the cable cannot be used for drone strikes or illegal mass surveillance.
It is also calling on BT to follow the British mobile operator Vodafone in publishing a transparency report, detailing the extent of its cooperation with government intelligence agencies around the world.
