Johannesburg - Humanity must "jealously guard" against racist tendencies in sport, President Jacob Zuma said on Friday.

"The world cannot allow sports to be used to perpetuate ideas which divide humanity and limit the ability of people to work together for development," Zuma said in a speech prepared for delivery at a summit in Kempton Park, on the East Rand, against racism in sport.

"There have been unfortunate and shocking incidents of blatant racism in sports being displayed around the world. We call upon the entire progressive humanity to frown upon racism in sports and to do everything humanly possible to put an end to it."

Zuma said discussions needed to be taken further to deal sufficiently with the causes of racism in all facets of social life.

South Africa this year celebrates 20 years of democracy, having previously lived under apartheid, which Zuma said was "an evil system based on institutionalised racism".

"Based on their race, South Africans were told where they could stay, live, go to school, which hospital to go to, where to play sports and literally every activity was determined on the colour of one's skin," he said.

Zuma said what happened in sport was a reflection of society in general.

"We must appreciate that sport is played in various political, social, cultural and economic contexts and is therefore not insulated from the influences of these contexts."

Sports people should not only defend their sport against racism, but skilfully use sports to actively eradicate it from society.

"Sports men and women must know that there is no scientific basis that can be used to advance the notion of racial superiority and inferiority in sport or anywhere else," he said.

"Pigmentation has absolutely nothing to do with a person's intellect, character and talents. What makes one good or bad at any sport is not their race or the colour of their skin."

He called on sports-loving people to undergo "ideological cleansing" to heal or protect themselves from "this disease of racism".