People had approached civil rights organisation AfriForum to take action against this crime, Julius Kleynhans, head of the group's environmental affairs, said in a statement.
According to Afriforum a total of 443 rhinos were poached in 2011, and 150 had been poached before the end of March this year.
Three veterinarians and five other men were expected in court in connection with the wrongful possession and distribution of scheduled veterinary drugs commonly used in rhino poaching. They face charges of contravening the Medicines and Related Substances Control Act.
They were Douw Grobler, formerly head of the Kruger National Park's wildlife capturing and veterinary services unit, state vet Dr Buti John Chibase, and private vet Johannes Gerhardus Kruger.
The other five were professional hunter Hugo Ras, and Matthys Christoffel Scheepers, Riaal Booysen, Johan Carl Heydenrych, and Christoffel Francois Naude.
All were arrested between August and November last year.
Activists for Animals Africa also intended protesting at the court. Spokeswoman Miranda Jordan said they wanted to create public awareness about the case.