US officials said today that an FBI probe into harassment claims uncovered the affair which led CIA director David Petraeus to resign last week.
General Petraeus stepped down when FBI agents confronted him over an affair with Paula Broadwell, who had been an embedded journalist in Afghanistan while he was in charge of occupying armies there and wrote a biography of him.
Ms Broadwell had come to the FBI's attention for sending allegedly threatening emails to another woman.
CIA officers had apparently raised concerns earlier about her "unprecedented" access to their boss.
Foreign Minister Alistair Burt's admission that the Cameron government has "supported" a survey of attitudes to US drone strikes in Pakistan's tribal areas amounts to a tacit admission of British involvement.