24 March 1993
On  24 March 1993; South African President F.W. de Klerk announced the existence of a South African nuclear programme as well as the fact that the Apartheid regime had successfully constructed six indigenous nuclear devices.  South Africa had initiated this programme to deter what it considered a major Soviet threat to its sovereignty. This also meant that these weapons were constructed to prop up the Apartheid regime. After having spent millions of rands developing the technologies necessary to enable the production of nuclear weapons, the Apartheid regime then completely dissolved and disassembled the entire programme  in the twilight of the negotiations between the Apartheid State and Liberation movements.
References

CNS, "South Africa's Nuclear Weapon Program: Lessons for US Non-Proliferation Policy", From James Martin Center for Nonproliferation Studies, [online], Available at cns.miis.edu [Accessed: 15 March 2010]|William & Marry, "A History and Review of South Africa’s Nuclear Weapons Program", From:William & Marry,[Online] Available at:www.wm.edu,[Accessed 11 March 2014].