A magistrates failure to ensure that a witness understood what it meant to take the prescribed oath has resulted in an Atlantis mans rape conviction and 16-year sentence being set aside.

A woman will appear in the Botshabelo Magistrate's Court after she allegedly strangled her two-year-old niece to death, Free State police said on Friday.

Constable Consolation Mokoale said the 19-year-old woman would face a murder charge in court on Monday.

She was arrested on Wednesday after the girl's naked body was found in a nearby veld.

The woman was held responsible for the murder because she was looking after the girl that day, Mokoale said.

Local residents were about to attack the woman at her home, but were stopped by the police. – Sapa