Lance Armstrong is facing a £78m lawsuit from the American government over his US Postal Service sponsorship.
The disgraced cyclist, who admitted to doping offences in January, is said to have been "unjustly enriched" during his Tour de France victories.
The lawsuit, which also names former USPS team director Johan Bruyneel and management company Tailwind Sports as defendants, is seeking triple losses of the service's sponsorship funds under the federal False Claims Act.
"Defendants were unjustly enriched to the extent of the payments and other benefits they received from the USPS, either directly or indirectly," reads the complaint.
Armstrong's attorney Elliot Peters has hit out at the allegations, calling them "opportunistic" and "insincere".
He said in a statement: "The US Postal Service benefited tremendously from its sponsorship of the cycling team. Its own studies repeatedly and conclusively prove this. The USPS was never the victim of fraud.
"Lance Armstrong rode his heart out for the USPS team, and gave the brand tremendous exposure during the sponsorship years."
The US Postal Service paid around $40m (£26.2m) to sponsor Armstrong's team for six of his Tour de France wins, as well as a salary exceeding $17.9m (£11.7m).
