In fact, MI5 had disclosed the man's status in phone calls to me, as it tried to persuade me not to investigate the man - known publicly only as agent X. The service aggressively maintained its ...

The head of MI5 has said he is concerned over new lines of communication between terrorists, particularly internet phone calls. In an interview with The Daily Telegraph yesterday, spy chief ...

But it said a senior MI5 officer had subsequently breached that policy by saying they had been legally authorised to say X was an agent and by confirming the man’s status in a recorded phone ...