Oscar Pistorius has been accused of concocting his evidence from the witness box to fit the prosecution case.
Pistorius was this morning accused of lying in court as he was cross-examined by prosecutor Gerrie Nel.
Mr Nel said: "Today I'm going to prove your version of events is untrue. That you tailored your version, concocted your story.
"Your version is so improbable that it cannot reasonably possibly be true."
Supporter grabs Pistorius' hand
Earlier, Pistorius was greeted outside the court by supporters with white balloons and Christians, playing and singing music.
One of the supporters clung to his hand for several seconds as he walked into the Pretoria court.
The athlete returned to the witness box for the fourth time to face more questions relating to the night he killed his girlfriend Reeva Steenkamp.
His account of the shooting has already been challenged in three days of tough interrogation.
On Friday, Pistorius said Ms Steenkamp did not scream or shout as he grabbed a gun and fired the shots that killed her.
The defendant said he could not explain why she had not shouted out, or screamed.
Tired & inconsistent
At one point on Friday the cross examination led an emotional Pistorius to admit he could be giving inconsistent answers because he was tired.
This prompted the judge, Thokozile Masipa, to ask if he was able to continue with his evidence.
Pistorius denies premeditated murder and illegally possessing ammunition in relation to Ms Steenkamp's death.
He also denies two further counts related to shooting a gun in public in separate incidents prior to the killing.