South African Olympic and Paralympic athlete Oscar Pistorius was involved in an argument at a nightclub over the weekend, local media has reported.
It comes days after his lawyers wrapped up their defence in his murder trial.
The Star newspaper said Mr Pistorius had an altercation with businessman Jared Mortimer at a club in Johannesburg's upmarket Sandton business district, reportedly after the athlete made disparaging comments about Mr Mortimer's friends.
Mr Pistorius' family spokeswoman Anneliese Burgess said the argument started after Mortimer started to "aggressively interrogate" Mr Pistorius about the murder trial.
"Our client regrets the decision to go into a public place and thereby invite unwelcome attention," she said in a statement.
The 27-year-old, known as 'Blade Runner' because of the carbon-fibre prosthetic running legs he uses, is on trial for the murder of his girlfriend, Reeva Steenkamp, whom he shot and killed at his luxury Pretoria home on Valentine's Day last year.
Mr Pistorius says he killed Ms Steenkamp after mistaking her for an intruder hiding in the toilet next to his bedroom.
The state accuses him of shooting her in cold blood after an argument.
The case was adjourned until 7 August to allow the legal teams to prepare closing arguments.
Judge Thokozile Masipa will then begin her deliberations, extending a trial that has already dragged on over four months.