Axed ANC Youth League head Julius Malema has lambasted President Jacob Zuma, The Times reported on Friday.
The paper said Malema was scheduled to deliver a public lecture at the Cape Peninsula University of Technology on former president Nelson Mandela on Thursday, but instead used the podium to criticise Zuma.
Malema labelled Zuma a "questionable leader", saying he was a laughing stock internationally who got married every December and used his culture to promote his multiple marriages.
"Zuma is a polygamist [who] undermined the rights of women," Malema was quoted as saying.
He also accused Zuma of avoiding the opportunity to answer to charges of corruption for which his former financial adviser, Schabir Schaik, was jailed.
The charges against Zuma were dropped.
Malema praised the leadership skills of Deputy President Kgalema Motlanthe.
"[He] takes the office of the [deputy] president very seriously."
The attack on Zuma's lifestyle was the second in the past week.
Speaking on a pre-recorded television youth show, African National Congress stalwart Winnie Madikizela-Mandela questioned how Zuma could promote the idea of one sexual partner to the youth when he had multiple wives.
The show is due to be broadcast in September.
President Zuma this week brushed off this criticism in a radio interview, saying it was "not wise to discuss personal things, unless those things impact on what you do".