24 August 1962
African delegations at the United Nations headquarters in New York requested Secretary-General U Thant to help obtain the release of Nelson Mandela, leader and co-founder of the ANC's armed wing Umkhonto we Sizwe. Mandela was arrested on 5 August 1962 near Howick, Natal, after being on the run for seventeen months and was imprisoned in the Johannesburg Fort. Three days later, the charges of leading workers to strike in 1961 and leaving the country illegally were read to him during a court appearance. In a statement, the African delegates condemned the arrest of Mandela and noted that he was held under the Sabotage Act, which carried a possible death penalty. They also believed he was unlikely to receive a fair trial.
References

Nelson mandela center of memory, (1962), "24 August 1962", from Nelson mandela center of memory, [Online], available at www.nelsonmandela.org [Accessed: 22 august 2013]