“We are busy taking action against the Australian media house [that has the video],” his attorney Brian Webber told Sapa.
“They have no right to broadcast the video. We will deal with it accordingly.”
The promotional video by Australian current affairs programme Sunday Night shows Pistorius walking on his stumps with an imaginary gun in his hand.
In another scene, Pistorius is seen carrying a woman out of his bathroom.
The website for the current affairs show said the video was “never before seen footage of Oscar Pistorius re-enacting the night he killed Reeva that convinced a top forensic expert he is innocent”.
The video was scheduled to air on Sunday.
National Prosecuting Authority spokesperson Nathi Ncube said it was not commenting on the video.
Pistorius’s family spokesperson Anneliese Burgess said the legal team was investigating the matter and “have asked for urgent clarification from Channel 7 in Australia”.
Pistorius faces a murder charge.
He claims he shot Steenkamp by accident through the locked door of his toilet in his Pretoria home on 14 February 2013, thinking she was an intruder.
The State argues he killed her during an argument.
Pistorius testified that he was on his stumps when he shot though the toilet door.
However, he said he put on his prosthesis before breaking down the door to get to Steenkamp.
Courtesy SAPA & AGENCIES ……… NEW AFRICA DAILY NEWS