A 12-year-old boy was drowned in a bath of boiling water by robbers who raped his mother before killing both his parents in a violent house robbery.

Three men broke into the family's home in Walkerville, Johannesburg, where they assaulted and shot dead Tony Viana, 53, and brutally raped and killed his wife, Geraldine.

They then tied up and gagged the sobbing boy, Amaro, and pushed him into a bath of boiling hot water to drown him, 'because he would be able to identify them'.