Cape Town – Lance Armstrong's confession has pushed South Africa's anti-doping body to retroactively test blood samples from over 50 top cyclists for EPO, bringing all major road and mountain races in the country last year under fresh scrutiny.

The South African Institute for Drug-Free Sport (Saids) said on Thursday the re-testing would help them, discover “if a major EPO doping problem exists in this country.”

South Africa's doping body banned David George, one of the country's best riders and a former teammate of Armstrong on the U.S. Postal Service team, for two years last month for EPO use – South Africa's first sanction for the blood-boosting substance, according to the body.

“Cycling is being damaged by these high-profile doping cases with a high sense of cynicism existing,” Saids chief executive Khalid Galant said in a statement announcing the sweeping retroactive tests. “These scandals have made it clear that we need to do our own due diligence to establish whether EPO doping is happening (in South Africa).”

Galant said Armstrong's admission to leading a sophisticated doping program, and George's positive result from an out-of-competition test last August, led Saids to re-test many of their “clear” samples from 2012.

“We need to clean up cycling. The excuse that 'everyone is doing it' does not wash,” Galant said. “Cyclists need to question their own values and not get dragged down by a culture of doping.”

Saids would focus on EPO testing, and the process had already begun using samples stored in a laboratory in Bloemfontein. Results would be out “in a few weeks,” Galant said.

Cyclists who doped also had an opportunity to come forward and confess and may receive reduced sanctions or be able to enter into plea bargains.

The positive test for EPO of two-time Commonwealth Games medalist and former Olympic cyclist George last year shook South African cycling. He rode with the disgraced Armstrong in 1999-2000.

Armstrong confessed in a television interview last week to doping during all of his seven Tour de France victories after years of denials and cover-ups. He has been banned for life by the United States Anti-Doping Agency and stripped of his Tour titles and Olympic medal. – Sapa-AP