The U.S. Anti-Doping Agency has brought formal charges against seven-time Tour de France cycling champion Lance Armstrong.

In a letter obtained by The Washington Post newspaper, officials accuse Armstrong of using several banned performance-enhancing drugs, including steroids and human-growth hormones. The letter says the charges are based on evidence uncovered during an investigation of his racing teams and interviews with witnesses.

Others charged include Armstrong's doctors, trainer, and manager.

The USADA does not have the authority to bring criminal charges against athletes. But it does have the power to ban Armstrong from Olympic sports for life and strip him of his seven Tour de France championships.

The U.S. Justice Department dropped a two-year investigation against Armstrong in February without charges.

Armstrong issued a statement Wednesday saying the anti-doping agency charges are baseless and motivated by spite. Armstrong says he has never doped in 25 years as an endurance athlete and has passed every one of his more than 500 drugs tests.