Armstrong now admits he used performance-enhancing drugs and has been stripped of those victories.
SCA Promotions filed its lawsuit Thursday in Dallas district court. The company tried to withhold the money in 2005 because of doping allegations but ultimately settled with Armstrong in arbitration.
Now SCA says Armstrong's admission proves a conspiracy to cheat and defraud the company into paying him millions.
The lawsuit also targets Armstrong agent Bill Stapleton as a defendant.
Armstrong's attorney did not immediately return a message.
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