The man, from Krugersdorp, was found guilty by the Johannesburg High Court sitting in Palm Ridge on Wednesday of raping their younger sibling by penetrating her vagina with his fingers, according to the report.

Twin sisters aged seven have helped to convict a man who raped their three-year-old sister, The Star reported on Thursday.

The man, from Krugersdorp, was found guilty by the Johannesburg High Court sitting in Palm Ridge on Wednesday of raping their younger sibling by penetrating her vagina with his fingers, according to the report.

The toddler bled for a week after the incident.

The twins, who witnessed the rape, were called to testify.

Judge George Maluleke praised their evidence and said the twins had been crucial to the case."

"In my view, the children remained consistent in their testimony and reasonably stood up well to cross examination," Maluleke was quoted as saying.

Prosecutor Deon van Wyk said the man had been found guilty of sexual assault of an 11-year-old girl in 2009. For that crime he received a five-year suspended sentence.