Carice Viljoen, who raced to the 27-year-old's home after he called her father for help, said the distressed athlete was "frantic" from the moment she stepped inside his house on Valentine's Day last year.Pistorius covered his ears with his hands as an emotional Ms Viljoen told the court: "He was saying, 'Please, please'. He was begging me to put her in the car and take her to the hospital.

"I was kneeling at Reeva's side and there was blood everywhere."

Ms Steenkamp was shot dead on February 14, 2013. Pic: Stimulii

Earlier, Ms Viljoen's father, Johan Stander, who worked on the luxury estate in South Africa where Pistorius lived, recalled the desperate phone call from the athlete in the early hours of the morning.

He told the court: "He said, 'Please, please, please come to my house, please. I shot Reeva. I thought she was an intruder. Please, please come quick.'"

He said he arrived at Pistorius' house around three minutes later to find the athlete "broken", "screaming" and carrying Ms Steenkamp's body down the stairs.

"Oscar was crying, really crying," he said. "He was in pain. He asked us to help him. He wanted us to put Reeva in a car and take her to hospital.

"We tried to calm him down. He was broken. He was screaming, crying, praying."

Ms Viljoen said she ran upstairs, grabbed a handful of towels and used them to try to stop the bleeding.

"Oscar was holding pressure on her hip," she said. "He had his finger in her mouth, trying to help her breathe.

"He just kept asking me, 'Where's the ambulance, where's the ambulance?'

"We tried our very best to keep her alive."

Mr Stander, who used to look after Pistorius' dogs when he was competing overseas, said the sprinter pleaded with Ms Steenkamp to "stay with him" and was "committed" to saving her.

Mr Stander said he found Pistorius carrying his girlfriend down the stairs

The witness, a former administrator at the Silver Woods estate, also told the court Pistorius would ask to be kept abreast of local crimes when he returned from his travels.

In one incident, he said, thieves broke through a fence and used a ladder to gain access to a house - a scenario the athlete has previously said he was concerned about.

A woman was tied up by intruders during another break-in, he added.

Pistorius' legal team are set to call ballistics, audio and psychological experts over the coming days, as the trial enters what is likely to prove a critical phase.

Pistorius admits shooting his partner but denies a charge of premeditated murder, claiming he mistook her for an intruder.

The trial continues.