The man who claimed to have been involved in an altercation with murder-accused Oscar Pistorius was seeking attention, Pistorius's family said on Tuesday.

"Mr [Jared] Mortimer, who has been unknown to Oscar and our family until he approached the press with his story of the so-called 'altercation' in which he has cast himself as the victim, is a man peddling untruths designed for maximum attention and maximum damage," the paralympic athlete's uncle, Leo Pistorius, said in a statement issued on behalf of the family.

Pistorius and Mortimer had a confrontation on Saturday at the upmarket VIP Room club situated at the Michelangelo Towers in Sandton, Johannesburg.

Through his spokesman, Pistorius on Monday said Mortimer "aggressively interrogated him" on matters relating to his murder trial.

Pistorius is charged with murdering his girlfriend, Reeva Steenkamp after he shot her through a locked toilet door at his Pretoria home on Valentine's Day last year. He alleges he mistook her for an intruder.

Mortimer reportedly told The Star newspaper that Pistorius insulted President Jacob Zuma's family and his own friends, resulting in the altercation.

"I took that personally because I am very good friends with a member of the Zuma family," he was quoted as saying.

He claimed Pistorius was intoxicated and started to poke him in the chest while they were talking. He then pushed Pistorius away from him and the paralympian fell over a chair. The bouncers reportedly intervened and asked Pistorius to leave.

Pistorius's family say, however, that Mortimer's version is untrue.

"My investigations indicate that Mortimer was the aggressor and eyewitnesses confirm this," said Leo Pistorius.

He also denied that Pistorius had offended the president's family.

"We wish to categorically state that there is absolutely no truth to this man's assertions that Oscar, for instance, insulted the president of South Africa or boasted about our family's so-called influence," he said.

"Oscar was at school with one of President Zuma's sons and liked him a lot. Oscar also has great appreciation of President's Zuma's extraordinary support of the paralympians."

The family also rubbished allegations that Pistorius claimed they owned the SA National Defence Force.

The Pistorius's said the paralympic athelete's move to venture into a public space while the trial was under way was unwise, but they had witnessed his "escalating sense of loneliness and alienation".

"This, we believe, is underlying some of his self-harming behaviour," Leo Pistorius said, adding that the family was finding ways of dealing with his isolation.

Meanwhile, the defence team in Pistorius's murder trial closed its case in the High Court in Pretoria last week. Final arguments are expected to be heard on August 7.