Guy Liddell, who worked for MI5, recorded that there was a breach in security at the embassy on 1943, which was later reported by ISOS, Intelligence Service Oliver Strachey. The leak involved an embassy diplomat bag and two agents. On Liddell talked to Stewart Menzies, head of the British Secret Intelligence Service. From the discussion Liddell learned that the leak of the diplomatic bag occurred during or after the air attaché brought it back from Cairo, which put not-yet-deployed re-ciphering tables at risk and required the abandonment of the tables. There were also missing blueprints for a gun at the office of a military attaché. Menzies stated that there was an investigation underway at the embassy, but nothing more was said about the leak for a few months.