(Adds Armstrong's estimated net worth, other details)
By Jonathan Stempel
June 19 (Reuters) - A federal judge on Thursday rejected Lance Armstrong's bid to dismiss a whistleblower lawsuit claiming that he and his former cycling team, which the U.S. Postal Service had sponsored, defrauded the government in a scheme to use banned, performance-enhancing drugs.
U.S. District Judge Robert Wilkins said complaints brought by the government and Armstrong's ex-teammate, Floyd Landis, were "rife with allegations that Armstrong had knowledge of the doping, and that he made false statements to conceal the doping and the attendant obligation which would have resulted if the government had known of the doping."
Armstrong, 42, was stripped of his seven Tour de France victories and banned for life from racing in 2012 by the U.S. Anti-Doping Agency after it accused him in a report of engineering one of the most sophisticated doping schemes in sports.
Armstrong, who had long denied using performance-enhancing drugs, admitted in January 2013 to doping and faces several civil lawsuits that could drain the fortune he accumulated as one of the world's most popular and successful athletes.
The cancer survivor's net worth, according to the New York Times, was estimated at $125 million in 2012.
Damages in the case before Wilkins in Washington, D.C., could top $100 million, court papers show.
Robert Luskin and Elliot Peters, two of Armstrong's lawyers, did not immediately respond to requests for comment.
They have argued that the Postal Service benefited from the valuable exposure it got from its sponsorship and that the lawsuit had been brought too late.
Paul Scott, a lawyer for Landis, did not immediately respond to a request for comment. U.S. Department of Justice spokesman Peter Carr declined to comment.
Landis, who lied about his own doping before confessing, originally brought the lawsuit in 2010 under a federal law, the False Claims Act, that lets whistleblowers pursue fraud cases on behalf of the government, and obtain rewards if successful.
He stands to gain up to 25 percent of whatever sum the government recovers.
The Justice Department joined the case in February 2013, hoping to recoup some of the estimated $40.5 million that the Postal Service paid from 1998 to 2004 for its logos to be displayed by Armstrong and his teammates from the now-defunct Tailwind Sports Corp during races.
Court papers submitted by Armstrong's lawyers this month show the government has been seeking more than $105 million from Armstrong, Tailwind and former team manager Johan Bruyneel.
That sum reflects triple damages under the False Claims Act for claims made after June 10, 2000, which was 10 years before the lawsuit began, the papers show.
In Thursday's decision, Wilkins also denied Bruyneel's request to dismiss the lawsuits against him.
Rebecca Worthington, a lawyer for Bruyneel, was not immediately available for comment.
The case is Landis v. Tailwind Sports Corp et al, U.S. District Court, District of Columbia, No. 10-00976. (Reporting by Jonathan Stempel in New York and Jonathan Kaminsky from Seattle; Editing by Howard Goller, Steve Gorman and Bill Trott)