Lieutenant-Colonel Thulani Zwane said 17-year-old Thando Madlala was last seen by a friend on Wednesday.
Her body was found at Masinenge informal settlement on Friday by locals and the police.
Zwane said it appeared Thando had been stabbed and her throat had been slit.
In a separate matter, 5-year-old Qophile Cele, from Mehlomnyama near Port Shepstone, on the South Coast, was last seen by her grandmother while playing outside her home at the end of August. The search for Qophile has entered the third week.
Zwane said Qophile had been wearing a red jacket, blue plastic shoes and grey tracksuit pants at the time of her disappearance.