The new Watchkeeper surveillance drone makes its maiden flight in the UK, April 14 2010.

The UK Ministry of Defence (MoD) will spend over half a billion pounds on acquiring and sustaining armed Reaper drones on operations in Afghanistan between 2007 and 2015, the Bureau of Investigative Journalism can confirm.

Ten years ago, CIA Predator drones are thought to have attacked a high-level Taliban meeting in Kabul, Afghanistan. The strike, which took place during the November 2001 invasion, is believed to be the first targeted assassination by an unmanned aircraft.

Since that date, the market for unmanned combat aerial vehicles (UCAVs) has grown rapidly, with the UK purchasing its first lethal drones in 2006: two Reapers from US manufacturer General Atomics. The UK MoD confirmed to the Bureau that it has budgeted to spend a further £506m with the company by 2015 on its armed drones programme.

The MoD first deployed Reapers in Afghanistan in November 2007 – with the system armed the following spring. The RAF drones are currently providing more than 1,200 hours of air support per month for the UK’s Afghan operations.

In December 2010 the Prime Minister David Cameron announced that the number of UK-owned Reapers was to increase to ten. A Ministry of Defence spokesman said the purchase would allow the Royal Air Force to have three Reapers flying simultaneously.