Cape Town - SA Rugby president Mark Alexander has hit out at critics suggesting there is a doping culture in South Africa rugby.

"You know, those who commented about our so-called drug culture can be charged with defamation. And what if we start talking about their drug culture?" Alexander said in an interview with Afrikaans newspaper Rapport.

Alexander was commenting after former Ireland lock Neil Francis made headlines earlier this month when he said an asterisk should be put next to the Springboks' Rugby World Cup triumph because of drug abuse.

"There is a problem in our schools, but all of us are working hard to try to solve it. Players were tested every day at the World Cup an no-one failed (a dope test)," the SA Rugby boss added.

Francis, who played 36 Tests for Ireland between 1987 to 1996, told the Irish Independent that he was "fairly certain" of a "steroid culture" in South Africa after Bok winger Aphiwe Dyantyi tested positive for "multiple" banned substances earlier this year.

Francis wrote:

In an interview with Sport24 last week, former Springbok lock Marco Wentzel said doping was a concern in the local game.

"The unfortunate fact is that if we look at the last few years in terms of the amount of rugby players caught doping, critics have a point. In recent times we have had the cases of Gerbrandt Grobler, Chiliboy Ralepelle and Aphiwe Dyantyi and way back we had the likes of Johan Ackermann. It's an issue and I don't think those who raise the issue are factually incorrect," Wentzel said.

READ | Marco Wentzel's full Q&A interview with Sport24

Alexander added that he was sorry to hear of Dyantyi's positive test and indicated that he felt the player did not know he was taking a banned substance.

The 25-year-old now faces a four-year ban from the sport