Supposedly new cellphone video footage taken by policemen of the Marikana shootings was seen by the Farlam commission of inquiry in November, commission chairperson Ian Farlam said on Tuesday.
"This footage had already been seen by the commission in November and a statement will be issued later today," he said in Rustenburg.
The video was released by Britain's Channel 4 News on Sunday, and shows how police kept their guns trained on two men while they crawled through a field.
It shows a tactical response team officer call for restraint while a miner is on the move.
"The guy is there running. Wait. Don't shoot him, don't shoot him," the officer shouts.
However, gunshots are heard and then the camera moves over the lifeless body of a man.
Another officer is heard saying: "That motherf**ker. I shot him at least 10 times."
The video is part of a broadcast in which journalist Inigo Gilmore reports that the dead man was later identified, and that he had been shot 12 times.
Later, a police officer is heard speaking in Afrikaans about someone having a smaller gun, and imitating the sounds of the gunshots.
Two policemen filmed the footage.
"[The police video was taken] a few hundred metres away from the media and, crucially, out of sight of their cameras, where most of the miners actually died," Gilmore reports.
The broadcast also shows footage shown by other media houses and during the inquiry.
Gilmore said the police video raised questions about what happened at the hill where 34 miners were killed and 78 wounded on 16 August, when police opened fire while trying to disperse a group gathered there.
In the preceding week, 10 people, including two police officers and the two security guards, were hacked to death.
On Monday, the video caused a stir on the social media website Twitter.
One person, @B_K_chronicles, tweeted: "I guess its safe to say cops simply murdered people in cold blood. This video tells a whole new angle now!"
A tweeter named @Fergs24 called the policeman's comments disgraceful and added: "I feel sick".
Another tweeter commented: "That Marikana shooting video report just reminds one of times best forgotten".
The commission continues in Rustenburg.