Presidential spokesman Mac Maharaj has denied reports that President Jacob Zuma went to Mexico to avoid being heckled at a Youth Day event he was scheduled to address at the weekend.

"The president is attending the G20 summit. That is the only purpose of coming here. Everything else is rumour," Maharaj said from Mexico on Monday.

"The [Youth Day] event was organised by the ANC and the NYDA [National Youth Development Agency]. Collins Chabane, in his capacity as Minister in the presidency represented president Zuma."

He said Zuma's program was "adjusted" so that he could attend the event. Zuma would also travel to Rio de Janeiro, Brazil, for the United Nations conference on Sustainable Development.

Zuma was scheduled to address a Youth Day event in Port Elizabeth on Saturday. On Friday it was announced that he would not be attending the event, and Chabane would speak in his place.

The Sunday Times reported that Zuma "dodged" the event because he expected to be booed and ridiculed by supporters of expelled African National Congress Youth League leader Julius Malema.

He was reportedly "inundated with pleas from his political inner circle" not to attend the event because he would be embarrassed.

It reported that "detractors" in the league believed the late announcement was a ploy to ensure that Deputy President Kgalema Motlanthe could not speak.

Motlanthe was reportedly favoured by the ANC Youth League to replace Zuma at the party's elective conference in Mangaung in December.

The Mail&Guardian reported on Friday that Eastern Cape ANC leaders were told not to provide the platform at the event for any of Zuma's potential presidential challengers.