JOHANNESBURG - Anonymity remained a top priority in court as the gemstones heist whistleblower known only as "Witness K" made her first appearance. Witness K alongside Suspended Ekurhuleni Deputy Police Chief Julius Mkhwanazi appeared before the Johannesburg Magistrate's Court on Monday on charges of fraud and robbery with aggravating circumstances. READ | Julius Mkhwanazi, Witness K to appear in court over gemstones theftThe pair are the last two of the suspects in the R15-million precious stones theft case. Mkhwanazi and Witness K spent the weekend behind bars following their arrest on Friday. During a testimony partially in camera at the Madlanga Commission, Witness K named Mkhwanazi as the mastermind behind the gemstone theft, which was disguised as a police operation.