JOHANNESBURG (Reuters) - South African Olympic and Paralympic track star Oscar Pistorius was involved in an argument at a night club over the weekend, his spokeswoman said on Tuesday, days after his lawyers wrapped up their defence in his murder trial.

The Star newspaper said Pistorius had an altercation with businessman Jared Mortimer at a club in Johannesburg's upmarket Sandton business district after the athlete made disparaging comments about Mortimer's friends.

Mortimer declined to comment when contacted by Reuters.

Try Newsweek for only $1.25 per week

But Pistorius' spokeswoman Anneliese Burgess said the argument started after Mortimer started to "aggressively interrogate" Pistorius about the murder trial, which has attracted huge domestic and international attention.

"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.

Pistorius says he killed 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.

During the trial, which opened in early March, the defence has sought to portray Pistorius as a vulnerable and caring boyfriend who killed 29-year-old Steenkamp accidentally.

The prosecution has argued Pistorius is a gun-obsessed hot-head who often lost his temper and who killed Steenkamp in a fit of rage after an argument.

The case was adjourned until Aug. 7 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.

Pistorius faces life in prison if convicted of murder.