The mutilated body of 11-year-old Tiyiselani Nokuthula Rikhotso, from Dengeza, outside Giyani in Limpopo, was found dumped in the local dam on Tuesday.
Police spokesperson Brig Motlafela Mojapelo said Rikhotso was reported missing on Monday.
Her body was found dumped in the Klein Letaba Dam by community members.
The motive for the murder was unknown.
No arrests were made.
