Oscar Pistorius reveals the shocking details of the night he killed Reeva Steenkamp.

Oscar Pistorius has given his first television interview since he fatally shot his girlfriend Reeva Steenkamp, revealing he can still recall the smell of her blood.

Speaking to veteran investigative journalist Mark Williams-Thomas from British network ITV, the Paralympian described what happened that fateful Valentine’s Day night in 2013.

“I did take Reeva’s life and I have to live with that,” he said according to The Guardian. “I can smell the blood. I can feel the warmness of it on my hands.”

The former sprinter gave the interview from his uncle’s Pretoria home where he remains under house arrest ahead of his sentencing for murder on July 6.

“I understand the pain people feel, that loved her and miss her,” he said during the interview. “I feel that same pain. I feel that same hate for myself. I feel that same difficulty in understanding this. And I look back and I think, I always think – how did this possibly happen? I think, how could this have happened? How could this have happened?”

Pistorius described the event in great detail, explaining that he thought he heard an intruder entering his home.

“This instant fear comes over me that there’s somebody in the house. Somebody’s was actually in the process of breaking in. And my first thing was thinking that I need to grab my firearm.”

He then claims he approached the bathroom on his stumps, shouting and screaming at the trespasser to get out.

“All I know is there’s somebody in my house. And all of a sudden I hear a noise, at the toilet. I presumed it was the toilet door opening and before I knew it I’d fired four shots.”

Via Getty.

His explanation?

"Reeva must have just gone to the bathroom. To relieve herself. And when I started shouting... she must have thought there was somebody coming in the passage off the balcony," he said.

"So she got scared and she closed the bathroom door and yet I'm thinking this is a confirmation of there being somebody in the bathroom. She just hears me shouting and me coming closer and closer to the bathroom."

The 29-year-old was originally convicted of culpable homicide (the equivalent of manslaughter in South Africa), but was forced to stand trial for murder after a successful Supreme Court appeal by prosecutors. That charge, says Pistorius, has been the most difficult thing to deal with.

"The day before we started the trial on March 2, 2014, I sat with my lawyers," Pistorius said. "I said to them, 'I will spend 10 years in jail for taking Reeva’s life, for culpable homicide, but I won’t spend a day in jail for murdering anyone'."

Pistorius already spent time behind bars for his original conviction, having been released in October 2015, one year into his five-year sentence.

"I don't want to go back to jail; I don't want to have to waste my life sitting there. If I was afforded the opportunity of redemption I would like to help the less fortunate, like I had in my past," he said, referring to his charitable work with landmine victims.

"I would like to believe that if Reeva could look down upon me, that she would want me to live that life."

Steenkamp's family declined ITV's invitation to participate in the programme, which will air locally on 60 Minutes this Sunday night.