ACDP leader the Reverend Kenneth Meshoe has labelled President Jacob Zuma a "sex addict" who should go for rehab.
"The president should go for sex addiction therapy as (golfer) Tiger Woods has done," Meshoe told Sowetan yesterday.
Meshoe was reacting to a Sunday Times report that Zuma fathered a love-child with soccer boss Irvin Khoza's daughter.
Sonono Khoza, 39, gave birth to a baby girl, Thandekile Matina Zuma, on October 8 last year.
Meshoe said in many democracies "he (Zuma) would be asked to step down because he was not setting a good example".
"The report is shocking and unfortunately it exposes that South Africans are not concerned about the moral foundation of this country because if they were they would challenge the president to straighten out his life," he said.
"We believe we are the laughing stock of the world when you have a president that has so many children all over."
Zuma has paid inhlawulo, a customary remuneration due when a child is born out of wedlock. Zuma now has 20 children with several wives and girlfriends.
Khoza and Zuma's spokespersons could not be reached for comment yesterday.
DA leader Helen Zille said: "President Jacob Zuma has undermined the struggle against HIV-Aids by having unprotected sex again.
"Zuma's behaviour directly contradicts the government's campaign against multiple sexual partners and the inherent Aids risk in having unprotected sex."
She said South Africa now had a president who, both through his words and actions, is doing damage to the struggle (against HIV-Aids) - a life and death struggle for millions of South Africans.
In 2006 Zuma was acquitted of raping the HIV-infected daughter of a close family friend.
Johannesburg high court Judge Willem van der Merwe found that Zuma had had consensual sex with her.
PAC president Letlapa Mphahlele said: "We won't judge the president based on media allegations."
The ANC could not be reached for comment.