AfriForum CEO Kallie Kriel said it was an attempt to show that Malema had "lied".
"Julius Malema told journalists outside court that he and [Mbuyiseni] Ndlozi didn't assault the policeman. It was important to show the public that he was lying," Kriel told News24.
Kriel also tweeted that Malema "isn’t known for being a truthful person".
Malema and Ndlozi have been charged with common assault.
The two appeared in the Randburg Magistrate's Court on Wednesday.
Addressing the media outside the courtroom, Malema said the case was a waste of the court's time.
When asked if he did assault the official he said: "I’ve never done that. I mean if I had laid a hand on him I would have panelbeated him. It would have been worse than what you saw. I don't play when I lay hands."
The matter was postponed to March 10, 2020, to allow the accused and National Prosecuting Authority time to hold consultations and make representations and disclosures before the trial starts.
On Wednesday, Kriel told reporters that everyone was equal before the law and that they would not allow anyone, including Malema, to assault a police officer.
"It doesn't matter what your surname is, even if your surname is Malema, you are not above the law," Kriel said outside court.