The US government is expected to join a lawsuit against former cyclist Lance Armstrong after talks with his lawyers broke down.

The suit argues Lance Armstrong defrauded the American public by insisting he was not using drugs while riding for the publicly funded US Postal Service team.

Last month, Lance Armstrong admitted using performance-enhancing drugs during all seven of his Tour de France wins.

The suit, filed by his former team-mate Floyd Landis, aims to recover sponsorship money from Lance Armstrong.

Armstrong’s legal team had tried to convince the US government not to join the so-called “whistleblowing” lawsuit filed by Floyd Landis, who himself admitted using drugs throughout his career.

But a statement by Lance Armstrong’s counsel Robert Luskin said: “Lance and his representatives worked constructively over these last weeks with federal lawyers to resolve this case fairly, but those talks failed because we disagree about whether the Postal Service was damaged.

“The Postal Services’s own studies show that the Service benefited tremendously from its sponsorship – benefits totalling more than $100 million.”

NBC News and the Wall Street Journal are both reporting the US government will now throw its weight behind the suit.

By flagging up allegations of fraud, Floyd Landis could receive a substantial share of any money recovered from Lance Armstrong under the federal False Claims Act.The law, introduced by President Abraham Lincoln in 1863, stipulates the person bringing the lawsuit can receive 15-25% of any damages.

The US government is expected to join a lawsuit against Lance Armstrong after talks with his lawyers broke down

Lance Armstrong, 41, ended years of denial in January during an interview with chat show host Oprah Winfrey in which he described doping as part of the process of winning the Tour.

He has since said he will not agree to be interviewed under oath by the United States Anti-Doping Agency (USADA).

Lance Armstrong was charged by USADA in June 2012 with using performance-enhancing drugs.

He filed a lawsuit against the organisation the following month, accusing it of “corrupt inducements” to other cyclists to testify against him.

However, Lance Armstrong then announced in August that he would not fight the doping charges filed against him, and was given a life ban by USADA and stripped of his Tour de France titles.

Lance Armstrong won seven Tour de France titles between 1999 and 2005. The US Postal Service sponsored the team between 1996 and 2004.