On Tuesday, proceedings were briefly halted after a South African TV channel showed an image of prosecution witness Michelle Burger.
At the time, Judge Thokozile Masipa described the incident as "disturbing" and ordered an investigation. She also warned the media to "behave."
Witness Charl Johnson, who lives near Pistorius, testified on Wednesday that he received a threatening phone call after his cell number was read out in court. The Olympian's lead defense lawyer Barry Roux later expressed remorse over the incident and Johnson accepted his apology.
The sprinter is accused of premeditated murder after fatally shooting girlfriend Reeva Steenkamp on Feb. 14, 2013. Pistorius insists he mistook her for an intruder.
The trial continues.