South African scientists are studying ways to inject radioactive material into rhino horns to make them easier to detect at border posts, a move to discourage poaching, a researcher said on Friday. Poachers killed at least 249 rhinos in South Africa during the first six months of the year - 83 more than in the first half of 2020. The animals are slaughtered for their horns, which are smuggled into Asia where they are highly prized for traditional and medicinal purposes. Injecting rhino horns with a small amount of radioactive material might deter poachers by making smuggling easier to detect, said James Larkin, a nuclear researcher at the University of the Witwatersrand.