Pressure is mounting on Hein Verbruggen, the head of the International Cycling Union during the Lance Armstrong era, to resign from his remaining posts on the organisation.

A report by the US anti-doping agency (USADA) has stated Armstrong was a serial drug-taker at the centre of a systematic programme of doping by members of his team US Postal during the late 1990s and early 2000s. UCI did not respond when asked to comment, but as recently as last year Verbruggen insisted seven-times Tour de France winner Armstrong had "never, never, never" used doping.

British cyclist David Millar told Press Association Sport: "The UCI have to accept they have to carry some responsibility for this because it was obvious what was going on. The UCI had all the blood data, the medical reports. It was part of the culture of the sport and in the big races the majority of riders were doing it on drugs."

He added: "There was only a tiny minority getting good results without drugs and they really were the outsiders. The first step for the UCI is that Verbruggen has to be removed.

The 71-year-old Dutchman, who is also an International Olympic Committee member, remains the UCI's honorary president and a member of the management committee.

Millar continued: "There is no doubt about that - (current president) Pat McQuaid has to distance himself because it was under Verbruggen's presidency that it was at its worst and yet there were all these denials coming from the UCI.

"He was at the head of organisation with the biggest doping problem in history of sport.He's still there. He doesn't have to commit hari kari - he should just admit that mistakes were made and we have all made mistakes.

"But the UCI is not a commercial company so there is no one to answer to."

The scandal claimed another casualty on Friday after it was announced that Johan Bruyneel, team director of the US Postal team during the Armstrong era, was quitting as general manager of the RadioShack Nissan Trek team by mutual agreement.

The USADA report states one rider testified "his use of prohibited substances was performed at the direction and with the full knowledge and approval of team director Johan Bruyneel".