Feds highly likely to join suit vs. Armstrong: AP

An attorney familiar with cyclist Lance Armstrong's legal problems said Tuesday that the Justice Department is highly likely to join a whistleblower lawsuit filed against Armstrong by former teammate Floyd Landis, The Associated Press reports.

CBS News has learned senior officials at the Justice Department have recommended that the government join that suit.

The False Claims Act lawsuit could result in Armstrong paying a substantial amount of money to the U.S. government. The deadline for the department to join the case is Thursday, though the department could seek an extension if necessary.

CBS News has learned Armstrong is in discussions with the Justice Department to return a part of the millions in taxpayer dollars received by his U.S. Postal Service team. However, the attorney told the AP, the two sides have very divergent views on the amount.

Armstrong has also indicated a willingness to testify against others involved in illegal doping, sources tell CBS News.

According to the attorney, who works outside the government, the lawsuit alleges that Armstrong defrauded the government based on his years of denying use of performance-enhancing drugs. The U.S. Postal Service was a longtime sponsor of Armstrong's racing career. Armstrong's U.S. Postal sponsorship prohibited illegal doping.

The attorney spoke on condition of anonymity because the source was not authorized to speak on the record about the matter.

After a decade of denial, Armstrong admitted in an interview with Oprah Winfrey taped Monday that he used performance-enhancing drugs to win the Tour de France, CBS News has learned. The interview is to be broadcast Thursday on Winfrey's network.

Separately, the government of South Australia state said Tuesday it will seek damages or compensation from Lance Armstrong in light of his confession to Winfrey.

South Australia Premier Jay Weatherill said the state would seek the repayment of several million dollars in appearance fees paid to Armstrong for competing in the Tour Down Under cycle race in 2009, 2010 and 2011.

Weatherill said Armstrong's apparent admission changed the government's view on its entitlement to compensation.

He said Armstrong "has deceived the cycling community around the world" by repeatedly denying he used performance-enhancing drugs during a career in which he won the Tour de France seven times.