The para-military branch of the South African / South-West African police in what is now Namibia are covered in 'Koevoet' by Jim Hooper: http://www.amazon.com/Koevoet-Jim-Hooper/dp/1868121674

There are two editions, I've got the early one(1988).

Hooper's book is not cited in: http://en.wikipedia.org/wiki/Koevoet

davidbfpo