Lance Armstrong could be subject to perjury charges after testifying in court that he had never taken banned performance-enhancing drugs, according to the US anti-doping agency.

The cyclist, named by USADA as being a central figure in a major doping scheme by the US Postal team, had told a court in Dallas under oath in 2005 he had never taken banned drugs.

Armstrong also told the court he had never violated the rules of the Tour de France, nor had the team doctor Michele Ferrari administered banned drugs to him. The USADA report, however, claims Armstrong's statements in court were false.

The report states: "As demonstrated by the testimony of numerous witnesses in this case, each of the above statements made under oath and subject to the penalties of perjury were materially false and misleading when made."

Meanwhile, the report highlights how the US Postal team were able to avoid detection of use of the banned blood-boosting agent EPO by injecting cyclists with saline just before tests to lower their blood cell count.

The report says: "The USPS team made regular use of saline infusions, a prohibited method, which permits a rider to quickly reduce his hematocrit level in order to beat the UCI's health check 50% hematocrit threshold and to fool the biological passport program.

"One of the bolder examples of the use of saline to fool the testers was at the 1998 World Championships when Armstrong's doctor literally smuggled past a UCI official a litre of saline concealed under his rain coat and administered it to Armstrong to lower his hematocrit right before a blood check."

The USADA report also states that Armstrong was guilty of "witness intimidation" when people testified against him or Ferrari.

At the 2004 Tour de France, the report says Armstrong told cyclist Filippo Simeoni, "You made a mistake when you testified against Ferrari . . . I can destroy you." and made a gesture of zipping his lips.

"Mr Armstrong's actions in connection with his threatening statement, constitute acts of attempted witness intimidation," says the USADA report.