spy for the U.S.S.R. who in March 1961 was sentenced to 25 years in prison by a British court.

Lonsdale's family moved to Poland in 1932, where he served, under various aliases, in the underground during World War II. He served in the Soviet military administration in Berlin after the war and then attended a university until 1950, when, posing as a German, he went to the United States to conduct intelligence activities for the Soviet Union.

In 1954 he was transferred to Great Britain, where, posing as a Canadian businessman named Gordon Arnold Lonsdale, he organized a group that gathered submarine detection secrets from the Underwater Detection Establishment at Portland, Dorset. Arrested on Jan. 7, 1961, he was tried for espionage with four other persons and imprisoned until April 22, 1964, when he was exchanged for the British intelligence agent Greville Wynne. His autobiography, Spy, was published in 1965.