Walter Hain, who has died in Wales at the age of 91, was an anti-apartheid activist who was raided, jailed, banned and effectively driven into exile in 1966. He was a friend of fellow Liberal Party member John Harris, who planted a bomb at the Johannesburg railway station in 1964 which killed a woman and horribly disfigured her granddaughter. Harris was hanged for this in 1965.Hain opposed violence because of the risk it posed to innocent people and because he believed it was usually counterproductive.But he and his wife, Adelaine, remained close to Harris and helped his wife, Ann, and their infant son during the nine months he was on trial.Harris asked Hain to deliver the address at his funeral. When the authorities refused to allow this, his son Peter Hain - later leader of the sports boycott against South Africa, and a British Labour Party cabinet minister - did so in his place.Hain was born on December 29 1924 in Durban. He attended Parktown Boys' High and Pretoria Boys' High before studying architecture at the University of the Witwatersrand. As an architect he specialised in the design of hospital laboratories.He joined the Royal Natal Carbineers and fought in Italy during World War 2.He married Adelaine Stocks from Port Alfred in 1948 and together they were gradually "radicalised". He said they were both political "late developers".A key moment came while he was working in Nairobi."India had just got independence," he told an interviewer, "and a whole lot of [British] ex-Indian Army people had come to Kenya, where black people were still kept in their place."One of the partners in the firm that I was working for said: 'Oh, we must learn from you South Africans. You know how to treat the blacks.' I had a hell of an argument with him."Back in South Africa they joined the Liberal Party of Margaret Ballinger and Alan Paton in 1954 and were active in its Pretoria branch: he became chairman and she its secretary.This brought them to the attention of the security police. In 1961 they were both jailed for two weeks without charge and then banned, she in 1963 and he a year later.They were the first married couple to be banned in South Africa and the government had to insert a special clause in their banning orders enabling them to talk to each other.It became impossible for him to earn an income after the government ordered architectural firms in the magisterial district of Pretoria, to which he was confined, not to employ him.In 1966 they moved to Britain where he joined the Anti-Apartheid Movement and helped start Architects Against Apartheid.He also became an active supporter of the sports boycott against South Africa. He threw himself into his son Peter's "Stop the Seventy Tour" campaign which played havoc with the 1969-70 Springbok rugby tour of Britain and forced the cancellation of the 1970 Springbok cricket tour.This was not easy for Hain, who loved cricket and rugby and had been an ardent Springbok fan. The vice-captain of the Springbok rugby team, Tommy Bedford, was an old friend and fellow architect.In 1972 a letter bomb addressed to Peter was sent to the Hains' home and opened by their daughter Sally. It did not explode.Hain is survived by his wife Adelaine and four children.1924-2016..