Lance Armstrong May Testify Under Oath About Doping

Feb. 6, 2013 — -- Facing a federal criminal investigation and a deadline that originally was tonight to tell all under oath to anti-doping authorities or lose his last chance at reducing his lifetime sporting ban, Lance Armstrong now may cooperate.

His apparent 11th-hour about-face, according to the U.S. Anti Doping Agency (USADA), suggests he might testify under oath and give full details to USADA of how he cheated for so long.

"We have been in communication with Mr. Armstrong and his representatives and we understand that he does want to be part of the solution and assist in the effort to clean up the sport of cycling," USADA CEO Travis T. Tygart said in a written statement this evening. "We have agreed to his request for an additional two weeks to work on details to hopefully allow for this to happen."

Neither Armstrong nor his attorney responded to emails seeking comment on the USADA announcement.

The news of Armstrong's possible and unexpected cooperation came a day after ABC News reported he was in the crosshairs of federal criminal investigators. According to a high-level source, "agents are actively investigating Armstrong for obstruction, witness tampering and intimidation" for allegedly threatening people who dared tell the truth about his cheating.

The case was re-ignited by Armstrong's confession last month to Oprah Winfrey that he doped his way to all seven of his Tour de France titles, telling Winfrey he used performance-enhancing drugs throughout his career and then lied about it. He made the confession after years of vehement denials that he cheated.

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If charges are ultimately filed, the consequences of "serious potential crimes" could be severe, ABC News legal analyst Dan Abrams said -- including "possible sentences up to five, 10 years."

Investigators are not concerned with the drug use, but Armstrong's behavior in trying to maintain his secret by allegedly threatening and interfering with potential witnesses.

Armstrong was previously under a separate federal investigation that reportedly looked at drug distribution, conspiracy and fraud allegations -- but that case was dropped without explanation a year ago. Sources at the time said that agents had recommended an indictment and could not understand why the case was suddenly dropped.

"There were plenty of people, even within federal law enforcement, who felt like he was getting preferential treatment," said T.J. Quinn, an investigative reporter with ESPN.

The pressures against Armstrong today are immense and include civil claims that could cost him tens of millions of dollars.

Armstrong is currently serving a lifetime ban in sport handed down by the U.S. Anti-Doping Agency, and today was the deadline he was given to cooperate under oath if he ever wanted the ban lifted.

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ABC News' Michael S. James contributed to this report.