The United States accused cyclist Lance Armstrong on Friday of defrauding the U.S. Postal Service by taking its sponsorship money at the same time he was doping and using performance-enhancing drugs in violation of cycling rules.

The government joined a civil suit against Armstrong, stripped of his seven Tour de France titles and banned for life from cycling in 2012 after accusations he had cheated for years. In January, he said the accusations were true in an interview with television host Oprah Winfrey.

A battle with the U.S. government over civil fraud charges threatens to sap what remains of the once-revered athlete's reputation, and hurt his wallet.

Armstrong and his teammates from Tailwind Sports wore the logo of the U.S. Postal Service during their record-breaking wins.

The sponsorship money totaled more than $30 million, the government said.

Armstrong plans to contest the suit because the Postal Service was not actually damaged, his lawyer, Robert Luskin, said.

Prosecutors have said they do not expect to charge him with a crime.

Presented by Adam Justice