PRETORIA, July 3: South African police on Friday detained the owner of a radio-controlled helicopter drone carrying a camera that was filming scenes around the Pretoria hospital where ailing anti-apartheid hero Nelson Mandela is being treated. F C Hamman, a South African freelance film-maker, was escorted away by police along with the helicopter camera he was flying with his 21-year-old son Timothy outside the clinic where Mandela, 94, has spent three weeks with a lung infection. (agencies)