Christian faith compels Reeva Steenkamp's parents to forgive Oscar Pistorius, but he must pay for what he has done.

This is the view of Reeva's mother, according to her husband Barry Steenkamp who gave testimony to a court on Tuesday. An emotional Steenkamp answered questions from both the prosecution and the defence and said his wife's Christian faith compelled her to forgive their daughter's murderer.

"She feels it's right in her heart to forgive Oscar," Barry Steenkamp said of his wife June.

"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."

Barry Steenkamp said he had found it more difficult to forgive Pistorius who will be given a fresh sentence after his initial conviction of culpable homicide was changed to murder at the end of last year.

"I feel the same, that Oscar has to pay for what he did. He has to pay for it." He said the sentence was "up to the court" and he would respect whatever decision was made.

 "I don't want to say that he has to go to the maximum," Steenkamp said, "but he has to pay for it."

Pistorius was initially convicted of manslaughter after he shot dead his girlfriend Reeva Steenkamp in February 2013. He served 10 months of his five year prison sentence and since October 2015 has lived under house arrest at his uncle's home.

However South Africa's supreme court overturned the ruling at the end of 2015 and found him guilty of murder, the worst crime under South African law.

He faces a jail sentence of 15 years but it may be reduced due to time already spent in prison and other factors. On Monday the defence argued Pistorius was a "broken" man and should be sentenced with community service rather than prison.

The sentencing continues.