The Johannesburg magistrate's court has sentenced a 63-year-old man to an effective 12-years in prison on charges of sexually assaulting a minor.

Johan du Bruyn was arrested in April 2018 after he touched and showed a nine-year-old girl pornographic material at a children's home in Langlaagte.

He was sentenced on Thursday, said Johannesburg police spokesperson Capt Xoli Mbele.

“The accused showed a nine-year-old girl pornographic videos. The little girl reported the matter to a social worker and he was suspended with immediate effect,” said Mbele.

“He also touched the bum of the little girl. He wanted the victim to show him her private parts and to take pictures of her private parts."

Investigating officer Sgt Cyprian Winna Baloyi of the family violence, child protection and sexual offences unit hailed the "good conviction", which he said was the result of diligent work by the police.

“We hope this sentence will scare away would-be offenders from committing the same crimes,” added Baloyi.