PRETORIA - The judge in Paralympian Oscar Pistorius' murder trial on Thursday told the prosecution to stop calling him a liar as Mr Gerrie Nel pressed with a line that the athlete was tailoring his testimony.
"Mind your language," Judge Thokozile Masipa told Mr Nel in the High Court, reported Bloomberg news agency.
"You don't call the witness a liar, not while he is in the witness box."
Pistorius, 27, has pleaded not guilty to murdering his girfriend Reeva Steenkamp on Valentine's Day last year. He maintains that she was an intruder in his bathroom when he fired four shots through a locked cubicle door.
The prosecution says he killed Ms Steenkamp, 29, in his Pretoria home after an argument.
Mr Nel said Pistorius committed mistakes during testimony, including a discrepancy from earlier statements on whether he turned off the alarm in his house after the shooting, because he was making up his answers to ensure his version of events added up.
"I think you are trying to cover up for lies," Mr Nel said. "You are tailoring evidence. There is no other reason for this."
Judge Masipa intervened to stop the questioning to ask if Pistorius was making mistakes because he's tired.
"Yes, I am tired, but that's not going to change anything," Pistorius responded, adding he was well enough to continue.
The court was adjourned for a brief while after this exchange on Pistorius' fifth day on the witness stand, and a fourth day in cross-examination.
The trial, which is being broadcast live on radio and TV, started on March 3. Only audio broadcast of Pistorius's testimony is allowed.