Two of the so-called "Waterkloof Four" who were released from prison under correctional supervision 18 months ago have been ordered back to prison, Beeld reported on Thursday. Three judges in the High Court in Pretoria ordered Reinach Tiedt and Gert van Schalkwyk -- who have each served just under three-and-a-half years in jail -- to return to Zonderwater Prison in Cullinan on July 10. The two, together with Christoff Becker and Frikkie du Preez, each received 12 years in prison after murdering a man in a Pretoria park in 2001. "We are stunned. We do not understand it," Tiedt's father Christoff Tiedt, said on Wednesday. Jenny Brewis, the pair's lawyer, said they had yet to study the court's decision and would decide whether to apply for leave to appeal against it. Judge Hans Fabricius said in his ruling on Wednesday it would be extremely unfair and inhumane to both Tiedt and Van Schalkwyk to be told to go back to jail immediately, as both had work and other responsibilities. A full bench of judges set aside district magistrate Peet Johnson's ruling of December 15, 2011, to convert the men's prison term to correctional supervision. An application had been brought by the minister and the correctional services department commissioner to set aside Johnson's order. Fabricius said the Criminal Procedure Act stated clearly that such a conversion application could not be made if a prisoner's release date was more than five years in the future.