Born Oct. 3, 1917, in Colombo. Figure in the Communist movement of Sri Lanka.
The son of a judge, Keineman graduated from Cambridge University in Great Britain. In 1943 he helped found the Communist Party of Sri Lanka (CPSL; known as the Communist Party of Ceylon until 1972). Keineman became a member of the Politburo of the Central Committee of the CPSL in 1943 and served as deputy general secretary of the Central Committee from 1950 to 1955. He was general secretary from 1943 to 1950 and from 1955 to 1972; he again held the post from 1975 to 1979. Between 1972 and 1975 he held the office of chairman of the CPSL.
From 1953 to 1957 and from 1964 to 1974, Keineman served as chairman of the Ceylon (Sri Lanka) Federation of Trade Unions. From May 1970 to February 1977 he was minister of housing construction and construction work.
Keineman was awarded the Order of Friendship of Peoples in 1977.