A video in which paralympian Oscar Pistorius allegedly refers to a gun as "a zombie stopper" caused a delay in his trial for murder in the High Court in Pretoria on Wednesday.

Judge Thokozile Masipa adjourned court for several minutes around 11am to consider a request by prosecutor Gerrie Nel to screen the video in court. Barry Roux, for Pistorius, had objected.

The video, of Pistorius and several other people at a shooting range, shows the murder accused firing at a watermelon with a handgun. As he hits it and it explodes, there are whoops of triumph.

"It's not as soft as brains but fuck it's a zombie stopper," a person who sounds much like Pistorius is heard saying. The video found its way online.

When Masipa returned to court she said she had considered the submissions by both Roux and Nel.

"This matter will stand down until the defence has had a chance to look at the video to make further submissions," Masipa said.

She did not say when the trial would continue.

Shortly before this Nel began his cross-examination by confronting Pistorius with the fact that he killed his girlfriend, words his defence has avoided using throughout the trial.

"You killed a person. You shot and killed Reeva Steenkamp," Nel snapped at him, and challenged him to take responsibility for this.

Pistorius shot Steenkamp, apparently thinking she was an intruder, through the locked door of his toilet on February 14 last year. He found her slumped over the toilet after he broke the door down. She was shot in the hip, arm, and head.

The athlete is charged with the murder of Steenkamp and with contraventions of the Firearms Control Act. He allegedly fired a shot from a Glock pistol under a table at a Johannesburg restaurant in January 2013. On September 30, 2012 he allegedly shot through the open sunroof of a car with his 9mm pistol while driving with friends in Modderfontein.