The British government may have permitted the use of its airspace and airports for clandestine American transportation of foreign prisoners more frequently than it initially acknowledged, according to a leaked document published Thursday in two British publications. The document – a memo said to have been written around Dec. 7 by a Foreign Office official, Irfan Siddiq, to Grace Cassy, an official in the office of Prime Minister Tony Blair – seems likely to deepen concerns across Europe about the extent of the flights, operated by the Central Intelligence Agency. Full Story