Police say a 21-year-old man has been arrested for the ax killings of a couple and their elder son but are not saying whether the man is the younger son who survived and calmly reported the assault.

Stellenbosch police spokesman Andre Traut told the African News Agency that the man turned himself in Monday afternoon and will appear in court Tuesday to face three charges of murder and one charge of attempted murder.

The ax attack in an upscale gated community in January 2015 killed Martin van Breda, his wife, Teresa, and their eldest son, Rudi. The family's daughter, Marli, was wounded.

Then-20-year-old Henri van Breda was lightly injured. The murders made headlines across South Africa but no arrest was made.