Olympic and Paralympic track star Oscar Pistorius (R) is hugged by a supporter as he arrives ahead of his trial for the murder of his girlfriend Reeva Steenkamp at the North Gauteng High Court in Pretoria, April 14, 2014. Pistorius is on trial for murdering Steenkamp at his suburban Pretoria home on Valentine's Day last year. He says he mistook her for an intruder.  [Photo/Agencies]

Nel also asked Pistorius if he was now changing his defence stance by saying he spoke to Reeva in a low tone asking her to call the police while earlier on he had said he whispered to her.

"I'm not choosing something to suit me," Pistorius responded.

The prosecutor also put it to him that if the noise he heard in the toilet was so loud, why did he not discuss it with Reeva before waking up to check.

"That doesn't make sense. That is not true -- it's improbable," Nel said.

Pistorius also broke down in tears when he narrated what he said when he shouted at what he thought was an intruder in his house.

"Get out of my house... Get the fuck out of my house," he said while crying uncontrollable forcing Judge Thokozile Masipa to adjourn the court to give him time to regain composure.

When asked why he pulled the trigger before seeing the alleged intruder, Pistorius said, "I don't know why."

Nel put it to him, "You shot at Reeva." This again caused the accused to break down in tears, saying, "It's not true."

Nel pressed on asking him why he did not give the alleged intruder time to leave since he was armed.

"I wasn't thinking of how they'd get out," Pistorius answered. He also insisted that he was just pointing his gun at the door without an intention of shooting anyone.

Pistorius also told the court that Reeva never screamed but it was him who first screamed at the alleged intruder then again calling Reeva.

"They (the neighbours) heard a woman screaming but it was you?" Nel asked. Pistorius replied saying, "That's correct, my lady. My voice is the only voice screaming that night."

Asked why he fired only four shots, Pistorius replied, "I'm not sure."

The court adjourned to Tuesday.