The boy was taken into custody on Saturday afternoon after police followed up information, said Sergeant Majang Skalkie.
She said the boy was later released under the supervision of his parents.
Retired professor Daniel Wybenga, previously of the University of Northwest, was found dead in the bathroom of his house in Clarens earlier this month.
His hands and feet were bound with rope and police suspect he had been strangled.
Wybenga’s gold-coloured Toyota Corolla, cellphone and music system were stolen from the house.
Two men were arrested soon after Wybenga, who lived alone, was found.
The men appeared in the Bethlehem Magistrate’s Court on charges of murder, house robbery and theft of a motor vehicle.
The case was postponed until Thursday for the court to hear their bail applications.