Another dramatic day in the sentencing of Oscar Pistorius. The former paralympian is facing up to 15 years in jail for murdering his girlfriend, Reeva Steenkamp, and on Tuesday, her father took the stand and told the court Pistorius must pay for his crime.

The first time Barry Steenkamp has addressed the court... and his testimony was heartbreaking. He began with the moment, in February 2013, that his wife phoned him.

"I couldn't really understand what she was so upset about, screaming and shouting. At first I thought it was probably one of our animals that was killed. She said come home immediately, come home. I dropped everything and on my way I tried to fathom out what she tried to tell me, then I realized that she mentioned Reeva. She said come come immediately Reeva's name was there and that's when I started to panic and driving home I realized that Reeva's been killed. It hit me then... it's like it happened yesterday," said Barry Steenkamp victim's father.

Pistorius shot Reeva Steenkamp - claiming he mistook her for an intruder. Barry Steenkamp told the court he tried to experience the pain his daughter had gone through.

"I don't know whether I was going mental or whatever but I used to take my fist and hit it against the wall with my knuckles, my injection from my diabetes, I used to take the needle and shove it and turn it into my stomach and my arms to see if I could feel the same type of pain but no. Oscar has to pay for what he did. He has to pay for it and that's all I have to say," he said.

"That is up to the courts my Lady. It's up to the court. And we will go by the decision that the court hands out to Oscar, but he has to pay for his crime. And I don't want to say that he must go to the maximum or whatever it is, but he has to pay for it," he said.

Both sides are calling witnesses this week - to try and influence the judge's sentence. Steenkamp's testimony will almost certainly count among the strongest.

Barry Steenkamp also told this court that while some people might disagree with him or think that he's callous, he wants the world to see all the pictures of his daughter after Oscar Pistorius killed her. He said he wants the world to see what happened to his daughter and perhaps that would deter others from possibly committing the same crime.

The prosecution team is to call its final witness Wednesday -  and says that testimony too will be emotional. Pistorius is expected to know his fate, on Friday.