Oscar Pistorius is holding weekly Bible studies with 'hardcore' inmates in prison, his father has said.
Pistorius, a former Paralympian, is serving life in a South African prison for the 2013 murder of his girlfriend, Reeva Steenkamp.
Henke Pistorius told The Times that his son, now 32, is 'making a difference' behind bars by meeting with other prisoners to study the Bible.
Despite being found guilty of Steenkamp's murder after a trial that gripped the world, Henke said his son had 'always been a true child of God'.
He told the newspaper things had improved for Oscar as a result of the weekly Bible meetings that he said were being attended by some of the most fearful inmates in the prison.
'I have no doubt that Oscar has changed the environment in the prison for the better, he is helping to mediate between people and is having a positive influence,' he said.
'He can feel he is making a difference to others who really needed a difference to be made — to give their lives meaning, purpose and some hope. As a result, things have also improved for him. It's a wonderful story.
'They are hardcore chaps, the problem people in the prison, but now they are all meeting to follow the Bible once or twice a week.'
During the trial, the court heard how Steenkamp's mother, June, had forgiven Oscar but still wanted to see him serve time for her daughter's death.
Reeva's father Barry Steenkamp told the court: 'She feels it's right in her heart to forgive Oscar. It still does not exonerate you for the crime that you committed. He must still understand that he has to pay for that.
'June has forgiven him so that she can carry on with her life.'
In April this year, Pistorius exhausted all of his legal options to have his sentence reduced after South Africa's highest court rejected his application for leave to appeal.
