By 1945, he was a major, having served as chief instructor for those joining the Control Commission in Germany and as Director of Studies at the Civil Affairs Staff Centre. He was awarded the United States Bronze Star. On demobilisation he rejoined the British Council in 1946.
He joined the Security Service in 1951.
F Branch and Singapore
He worked in MI5's protective security branch for ten years and was detached for a year to the Civil Service Department, serving as secretary and adviser to the committee of inquiry into protective security procedures that had been set up under Lord Helsby.
D Branch/K Branch
He worked for five years in the counter-espionage branch, where he was responsible for a a series of complex and delicate investigations, including one which led to the arrest and conviction of civil servant Frank Bossard as a Soviet spy.
During this time he was also involved in the Graham Mitchell case, as part of the investigation into possible Soviet penetration of MI5. He ultimately became convinced of Mitchell's innocence. By the time of his second report, Anthony Blunt had confessed to spying for the Russians, and Symonds concluded that he was the mole. Roger Hollis agreed and Mitchell was cleared of all allegations. Symonds denied suggestions that he had retained doubts about Mitchell, and contemplated libel action.
Deputy Director General
He was appointed Deputy Director-General in 1972 and assumed temporary charge of MI5 between December 1973 and March 1974 when Michael Hanley was ill. He was appointed CB in 1975 and retired a year later.
From 1976 to 1978 he served on the staff of the Royal Commission on Gambling.
Symonds died on 21 December 1998 aged 81.
- Ronald Symonds, The Times, 1 January 1998.