Mbeki said in response to a question after a speech to the University of Stellenbosch Business School that he thought the social media tool was not appropriate for discussing knowledge meant for the betterment of society.
“I am sceptical about this notion of Twitter being that great conveyor instrument for the democratisation of knowledge,” Mbeki said at the start of the school's knowledge conference.
“If you want to discuss knowledge which has got to do with the betterment of society I don't think it is appropriate.
“Even the internet in general, blogging and so on, is not the place where you can… put all these things under theories."
In his speech Mbeki questioned whether knowledge had become “less democratised and more compromised” as an instrument for the improvement of society. He said traditional media institutions were unable to control which political rhetoric "caught fire" with the public.
It was difficult investigate claims and counter-claims, he said. The conference should look into how false knowledge was "advanced" by groups with agendas.
He suggested that "false knowledge" was used to remove slain Libyan leader Muammar Gaddafi from power.
“False knowledge was advanced that the Gaddafi regime was about to slaughter millions of civilians,” Mbeki said.
"This was to justify the imposition of a 'no-fly zone' over Libya which served as a cover to overthrow the Libyan government and impose a regime approved by the Western Powers in their interest."
The Council of Europe had also asserted that "false knowledge" was propagated about a swine flu epidemic in 2009 to benefit highly profitable pharmaceutical companies.
Media still influential
Mbeki said the media remained very influential in South Africa.
“It becomes a very important vehicle for the conveyance of that knowledge,” he said.
“Particularly [where] readers seem to have sufficient confidence in the media, so they think if it comes from newspaper it is true.
"Thabo Mbeki stole half a dozen eggs from supermarket. Therefore it is true because it comes from the newspaper."