Murder accused Sandile Mantsoe allegedly disclosed to police officials that he burnt his on-and-off girlfriend, Karabo Mokoena, as a sacrifice for his business. This was the testimony offered by Karabo's sister, Bontle, in the South Gauteng High Court in Johannesburg on Tuesday. Bontle is the State's second witness in the case. She said the police initially approached her mother at the police station and soon after she heard her screaming. "They (police) told us that Sandile was involved in some businesses and in order for his business to succeed he needed to sacrifice someone and that sacrifice was Karabo," Bontle said. Mantsoe is facing a charge of the premeditated murder of Karabo, who was killed on April 28, 2017.'He will kill you one day'Karabo's charred remains were discovered in an open veld in Lyndhurst, Johannesburg. Mantsoe is also charged with assault with the intent to do grievous bodily harm for allegedly assaulting Karabo on March 27, 2017.He pleaded not guilty to the charges. Court 4C had to adjourn a few times on Tuesday as Bontle broke down during her testimony. Read: 'She was the other half of me' – Karabo Mokoena’s sister on the first year without herShe also told the court that Karabo would do anything for the accused.Her mother would warn her: "Karabo please leave this man, he will kill you one day."Passport, ID found in binBontle said when her sister went missing in April 2017, family and friends launched a search operation. They also went looking for her at Mantsoe's apartment in Sandton, but it is alleged that he told them that he had not seen her since they broke up in April.One of the managers showed them CCTV footage of her sister walking in and out with Mantsoe. She said the security guard at the hotel also gave her Karabo's passport and identity book which were apparently found in a dustbin in the apartment building. Bontle also told the court that on Karabo's birthday on March 27, Mantsoe allegedly assaulted her. She said when she went to fetch her sister in hospital the following day, she found her with bruises on her neck, eye and leg.She took her to Mantsoe's place to fetch her things, but Karabo refused to go home, fearing that her father would see her bruises. She instead went to a friend's place. Claims of suicideBontle said this was not the only time her sister was allegedly assaulted by Mantsoe. "There was this time Karabo found Sandile with another girl in a hotel and [he] head-butted her," Bontle said. On Monday, the State called its first witness, Stephanie Leong, who had been friends with Karabo since 2013.She described Karabo as a "bubbly" and "strong-willed" person. Mantsoe, a married father of three, had reportedly been in a romantic relationship with Karabo since October 2016. It is believed that he and his wife were estranged.The accused has denied killing Karabo but during his bail application, he said he had disposed of her body after he came home and found that she had committed suicide.