A ‘high level’ source has confirmed that Lance Armstrong is being actively investigated for obstruction, witness tampering and intimidation, raising the prospect that criminal charges may yet be brought against the disgraced cyclist. The revelation contrasts with an insistence yesterday by the federal prosecutor who last year closed an investigation against Armstrong that there were no plans to re-open that probe.

Yesterday, speaking at a press conference on an unrelated issue, André Birotte, United States Attorney for the Central District of California, said there were no plans to reopen the two year investigation he led into Armstrong, which was dropped suddenly in February last year.

"We made a decision on that case a little over a year ago,” he maintained. “Obviously, we've been well aware of the statements that have been made by Mr. Armstrong in other media reports. That does not change my view at this time."

While that may be true for the specific investigation he headed, which focused on drug trafficking, misuse of federal funds and fraud, an unnamed ‘high level’ source, speaking to ABC News on condition of anonymity, maintained: "Birotte does not speak for the federal government as a whole."

The source added: "Agents are actively investigating Armstrong for obstruction, witness tampering and intimidation."