Jonas Dinous Matlou was born 2 June 1920 in Diepsloot north of Johannesburg. He became an early member of the African National Congress Youth League (ANCYL) when it was found in 1944. In the 1950s he was very active in the ANC'S unsuccessful campaign to forestall the removal of Africans from the area, which whites find to be too near the central city.
In December 1956 Matlou, sometimes described as a "firebrand", was one of the people arrested on a charge of treason, but charges against him were withdrawn a year later. In 1960 the ANC was declared illegal, Matlou moved to Lobatse in Bechuanaland(now Botswana) with his family, establishing a way-station for exiles going north to escape arrest in South Africa or to train as members of Umkhonto we Sizwe(MK), the ANC's armed wing. He underwent military training in the Soviet Union.
In the mid-1960s Matlou was co-opted into the ANC's National Executive Committee (NEC). In April 1969 Morogoro, Matlou was one of the people dropped from the NEC when it was decided to reduce the committee from 23 members to 9. In 1975 September Maltou with Tennyson and Ambrose Makiwane and five others,he was expelled from the ANC. He later returned to Ghana where he earned a law degree and practiced law until returning to Botswana in 1985, then to South Africa after the exile movement were unbanned in 1990.