An unmanned drone said to be the most technologically advanced aircraft ever built in Britain has made its first successful test flights, military chiefs announced on Wednesday.

The 185 million pounds ($302 million, 223 million euros) top-secret Taranis craft, named after the Celtic god of thunder, conducted the tests at an unnamed location, believed to be in the Australian desert, in August last year, the Ministry of Defence (MoD) revealed at a briefing in London.

It was designed and built by BAE Systems, Rolls-Royce, GE Aviation and QinetiQ, working alongside MoD military staff, and was funded by the government and the UK defence industry.

The pilotless aircraft was first unveiled by BAE at a glitzy ceremony in 2010 but has since been kept under wraps.

Nigel Whitehead, group managing director of BAE Systems, called Taranis the "pinnacle of British engineering".

He said Taranis had performed a perfect take-off, rotation, "climb-out" and landing.

Test pilot Bob Fraser was forbidden from giving precise details about the craft's speed and altitude capabilities, but revealed it flew at least "twice as fast" as any other drone he has operated remotely.

It is reported to fly faster than the speed of sound, and is the prototype for the UK's first stealth combat drone, due to be operational in the 2030s.

Philip Dunne, minister for defence equipment, support and technology, called it "the most advanced air system yet conceived, designed, and built in the UK".

"Taranis is providing vital insights that will help shape future capabilities for our armed forces in coming decades," he added.