A little-known organisation is gunning for minority rights group AfriForum after its chief executive, Kallie Kriel, said apartheid was not a crime against humanity.

The Black Centric Forum (BCF) on Saturday laid criminal charges against Kriel at Hillbrow Police Station, Johannesburg, accusing him of hate speech.

The BCF's spokeswoman, Theko Nkadimeng, said the criminal charge was meant to send a strong message to people who say things to offend black people in general.

"The case is about hate speech because BCF is a pro-black movement and we've noticed that after (24 years of democratic dispensation), we're still being oppressed via what (AfriForum) is saying to us," said Nkadimeng.

"We've got to show them we can stand on our own. We can't (when they offend us) keep on whining on (social media) and not do anything. These people need to know when they are wrong.

"It's not a matter of fighting them but it's about saying this South Africa is about diversity but, honestly, that's just on paper, which is the Constitution.

"If somebody can say (what Kriel) said in public and we don't do anything about it, (we'll be sending a message) that we're still inferior to them."

Last month Kriel said during a radio interview that not enough people were killed during apartheid to justify it being called a crime against humanity.

"In the '80s and early '90s people died during the people's war conducted by the ANC," Kriel said.

Nkadimeng said the BCF would not mind seeing Kriel go to jail for the comment.

Kriel, via SMS, said: "Their complaint has no legal grounds and will fail. It seems they're an unknown organisation trying to make a name for themselves by making cases with no substance."