The British government has been asked to investigate whether the country’s major provider of telecommunications networks and services, BT, is aiding US drone strikes.

According to a complaint filed by the charity group Reprieve, BT has built a military internet cable connecting US air force facilities in Northamptonshire to a base for unmanned craft in Djibouti on the Horn of Africa.

The human rights group alleges that the $23 million (£13 million) fiber-optic circuit built by BT in 2012 was installed to facilitate air strikes in Yemen and Somalia by US Air Force drones.

Reprieve investigator Kevin Lo said: “Between this new evidence, and BT’s claim to work with ‘any government that pays the bills’, it’s now clear there are serious questions to be asked about BT’s possible support for US drone strikes. The government should reopen its investigation as soon as possible, and demand some answers on behalf of the strikes’ civilian victims.”

The fiber-optic cable runs from the Royal Air Force Station (RAF) Croughton in central UK to Camp Lemonnier in Djibouti, which houses the Pentagon’s most important base for drone operations outside Afghanistan.

BT, however, said the circuit is a general purpose system not specifically designed or adapted by BT for military purposes, including drone strikes.

Reprieve said that since the strikes take place in countries with which the US is not at war and have killed civilians, "they violate international and domestic law.”

There have been as many as 60 confirmed drone attacks in Yemen since 2012, with 385 killed, including 47 civilians and five children, according to the Bureau of Investigative Journalism.

BT’s contract is set to run until October 2017. The circuit apparently not only connects Djibouti to the UK, but also to Capodichino near Naples in Italy, where the US navy has its European and African command centres.

Reprieve is acting on behalf of two Yemeni men whose relatives were accidentally killed by drones.

The complaint also includes evidence of BT’s apparent complicity with intelligence agencies GCHQ and the NSA to engage in covert mass surveillance, “providing information that is used to target the victims of drone strikes.”

Reprieve is urging BT to follow Vodafone in publishing a transparency report, detailing the extent of its cooperation with government intelligence agencies around the world.