Five suspects are expected to appear in the Randburg Magistrates Court on Monday morning for the murder of Prince Lethukuthula Zulu.
The 50-year-old son of King Goodwill Zwelithini was found dead by security guards at his Northworld home earlier this month.
Pretoria police arrested four women and man on Friday for their alleged involvement in the killing.
The case changed from an inquest to a murder investigation. Police said that critical evidence obtained by forensic experts linked the suspects to the scene of the crime.
During their arrest, one suspect was found in possession of various substances.
Authorities said that they would run tests to determine whether the Prince and his business partner were drugged before money and other items were stolen.
Suspected stolen goods were also found at the homes of the suspects.
“The investigation continues as police envisage to possibly uncover more evidence towards building a solid case that can stand in court,” said police spokesperson Brigadier Mathapelo Peters in a statement on Sunday.
“The investigation might also assist in establishing whether the suspects might have committed previous similar crimes where victims were drugged and robbed,” she added.
The suspects are expected to face a charge of murder and theft in court.