Alexander Otten, 53, was found with his hands and feet tied and a plastic bag over his head, reported the Cape Times.
Otten’s wife, Jo, and two children were said to be in a state of shock.
“[Though] very traumatic for the whole family, we are a big family and are pulling together,” said Otten’s brother, Theo.
He said his brother had gone to his holiday home to do maintenance and repair work.
The house was one of four luxury units on a farm and game lodge near Velddrif, all fitted with security alarms.
“Jo had tried to speak to him a few times, but his phone was off, which was very unusual.”
“What has happened is shocking and horrible. Theo was a very honourable and just man. He was an absolute gentleman and his friends loved him,” Otten said.
The farm owner’s daughter, Elaine Venter, said: “This is a big shock to the family and to all our visitors that come here to relax. This is the first time this has happened.
“Our visitors come here thinking that they have left the crime and hustle and bustle of the city behind, but now one person comes here and he gets murdered. This is totally unacceptable.”
“This is private land and here you do not expect anything like this to happen. We won’t have any peace in this little community now.”
Two suspects were arrested in St Helena Bay on Monday, and are due to appear in the Vredenburg Magistrate's Court on Wednesday.