London: American spy agencies refused to give British intelligence services full details of a "Mumbai-style" terrorist plot in the country, fearing their top-secret sources may get exposed, the Daily Telegraph has reported.
The CIA had warned the British secret intelligence service, MI6, that al Qaeda was planning an attack 18 months ago. But it withheld detailed information because of concerns that it would be released by British courts, the Daily Telegraph reported.
British intelligence agencies were subsequently forced to carry out their own investigations, according to Whitehall sources.
Several potential terrorists were identified with links to a wider European plot, but it is still unknown whether the British authorities have uncovered the full extent of the threat.
The breakdown in relations came after the release of US intelligence in the case of Binyam Mohamed, a former Guantánamo Bay detainee who took legal action over his incarceration.
The government was subsequently forced to pay millions in compensation to him and other detainees.