Leak shows CIA's secret drone base in Saudi Arabia - The Times (subscription)

The incoming head of the Central Intelligence Agency is likely to be asked today about the legal advice given to justify the killing of three Americans in attacks by US drones flying from a covert base in Saudi Arabia.

A Justice Department document leaked this week revealed that the Government has sanctioned the killing of US citizens overseas if they are leaders of al-Qaeda or associated groups and judged to pose an "imminent threat".

The leak appears timed to place the Government on the defensive before John Brennan's nomination hearing today. The White House has fought to keep its expanding campaign of covert air strikes out of the public eye.

The document, obtained by NBC News, revealed a secret CIA base in Saudi Arabia set up by Mr Brennan to carry out drone strikes against al-Qaeda targets in Yemen. The base was used to launch the attack in September 2011 that killed Anwar al-Awlaki, the American-born cleric linked to a string of attacks on US soil.

That attack, also killed Samir Khan, another US citizen, and two weeks later a strike killed the preacher's 16-year-old son. The deaths have prompted a lawsuit accusing the US Government of authorising unlawful killings.

President Obama has rapidly expanded America's use of drones against terror suspects in Yemen, Somalia, Pakistan and Afghanistan.

Mr Brennan is the main architect of the administration's drone strategy.

A former CIA station chief in Saudi Arabia, Mr Brennan used his contacts in Riyadh to begin building a drone base in the kingdom. The Times revealed in July 2011 that King Khaled air base at Khamis Mushait, close to the kingdom's southern border with Yemen, was the most likely location for the secret base.