His MI6 career was notable for his involvement with the Lionel Crabb affair in the 1950s and the flight of double agent Kim Philby to Moscow in 1963.

[1] After leaving Trinity College, Cambridge, Elliott was offered a post in 1938 as Honorary Attache at The Hague by Sir Nevile Bland.

Stationed in Istanbul, he was instrumental in the recruitment of Erich Vermehren, who provided the British with detailed confidential information on the workings of German intelligence.

[4] Elliott's intelligence career was marked by two extraordinary events: the death of Royal Navy Commander Lionel Crabb in 1956, and the flight of British double agent Kim Philby to Moscow in 1963.

He made one run under the ship, came back for an extra pound weight for his next attempt and failed to return from the second dive.

The matter leaked, Prime Minister Anthony Eden protested that he had not been informed, and adverse publicity ensued.

[1] The British espionage television series, A Spy Among Friends, based on the book by Ben Macintyre depicts Elliott's role in Philby's career.