8 September 1967
It was officially disclosed that the South African Police (SAP) were in Rhodesia (later renamed Zimbabwe) actively helping in the fight against Nationalist guerrillas. This follows an attempt by several hundred guerrillas to invade South and South West Africa (renamed Namibia), from Zambia, at the urging of the Liberation Committee of the Organisation of African Unity (OAU) in Kampala in July, 1967. The Rhodesian authorities closed Operation NICKEL on 8 September 1967, as they were satisfied that all the guerrillas in Rhodesia had been accounted for. In spite of this, the South African units remained in Rhodesia in readiness for any future guerrilla strike.Click here to read Nicole (Nicky) Van Driel's thesis on South African Police's involvement in the Wankie Campaign.
References

Van Driel, N., The Wankie Campaign, from South African History Online, [online], Available at www.sahistory.org.za [Accessed: 05 September 2014]|Mackie, R., (2013), A history of Apartheid in South Africa from 1930 until 1960, from South African Hotels, 17 April [online], Available at www.south-african-hotels.com [Accessed: 05 September 2014]