sentences:  He supported the National Union of South African Students, and was chairman of the Defence and Aid Fund, which funded the defence of those accused of political crimes and supported their families, until it was banned in 1966.In July 1967, the Prime Minister John Vorster imposed a banning order under the Suppression of Communism Act which prohibited him from all political and social activity for 5 years.By now, he had an international reputation as a leading endocrinologist, and the banning order led to widespread protest.