Oscar Pistorius is battling accusations that he snapped at a friend of slain girlfriend Reeva Steenkamp in a South African court, muttering a "sinister" remark to her.
Kim Myers, one of Steenkamp's closest friends, accused Pistorius Tuesday of trying to intimidate her as they passed one another, alleging that he said, "How can you sleep at night?"
Myers' attorney, Ian Levitt, called Pistorius' alleged tone "sinister," saying Myers was shocked and found the situation "extremely disturbing."
"It's important to confirm this," Levitt said of the alleged comment. "It was in front of witnesses. Journalists have witnessed this."
Levitt was not in the Pretoria courtroom but said Myers phoned him to report it.
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Pistorius' lawyer, Brian Webber, said Pistorius told him that the allegation was untrue. "I've asked the client and he denies that he said it," Webber said.
Myers, a potential witness for the prosecution, criticized Pistorius in public after the shooting, saying, "We trust and hope that justice will prevail."
While no one other than Myers claims to have heard him say anything to her, former New York prosecutor Dan Schorr said the dispute reflects the growing anxiety in the courtroom.
"Tensions are going to be high at any trial at this point, and you can see it from this accusation that tensions are really starting to explode," Schorr, who has no connection to the case, said.
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Beyond tensions, court costs are also building, forcing Pistorius, 27, to sell his house - the house where Steenkamp died - Tuesday at a discounted price.
With the defense wrapping up its case, a verdict is possible by the end of the month, sources told ABC News.
The athlete, who's known as "Blade Runner" for his prosthetic legs, is accused of premeditated murder in Steenkamp's death. He has argued that he mistook her for an intruder.
Court was not in session today because of elections in South Africa, but the trial will resume Thursday.
The Associated Press contributed to this report.
Steenkamp's Friend Accuses Pistorius of 'Sinister' Remark