The World Anti-Doping Agency on Tuesday urged U.S. federal authorities to quickly hand over evidence collected in their lengthy probe into seven-time Tour de France winner Lance Armstrong and doping in American cycling.

WADA president John Fahey said federal agencies in the United States gathered "significant evidence" in the criminal investigation that was abruptly closed last week with no charges filed and no explanation given.

Fahey said it would be "very, very helpful if that information was handed over" to the U.S Anti-Doping Agency. That agency has said it will continue its own probe into doping in cycling.

Federal prosecutors dropped the investigation of Armstrong last Friday, ending a nearly two-year effort aimed at determining whether the world's most famous cyclist and his teammates joined in a doping program during his greatest years.

"There has been significant evidence taken on anti-doping areas, on what may have occurred in the way of doping. It would be very, very helpful if that information was handed over," Fahey said of the U.S. probe that was led by federal agent Jeff Novitzky, who also investigated baseball players Barry Bonds and Roger Clemens.

"The United States anti-doping organization is keen to get hold of that evidence and we would like to see that happen because there could well be some very relevant information there," Fahey said.

WADA's director general, David Howman, noted that U.S. federal agencies previously shared evidence gathered in their probe of the Bay Area Laboratory Co-Operative steroid distribution ring that brought down American sprinter Marion Jones and others.

He said WADA anticipates that evidence from the Armstrong probe "will be shared in the same way" and expressed hope that could be done in the six months before the London Olympics open in July.

"It is important that that happen as quickly as possible, just in case there are athletes who might be looking at going to London and where there is evidence in relation to them," he said.

Armstrong is now retired.

"If we receive a formal request for information or evidence gathered during our investigation, we will consider the request in light of our obligations under DOJ policy and federal law and respond accordingly," said Thom Mrozek, a spokesman for the U.S. attorney's office in Los Angeles.

WADA's world anti-doping code has an 8-year statute of limitations for doping offenses. That raises questions about whether USADA would be able to make full use of evidence gathered in the federal probe and, if needed, initiate proceedings against Armstrong or any other rider for supposed offenses that may have happened before 2004. The federal probe was thought to have focused on the period when Armstrong rode for the U.S. Postal cycling team until 2004.

But Howman cited the case of American runner and Olympian Eddy Hellebuyck to suggest that there can be exceptions to the 8-year limit.

Last week, USADA announced that a U.S. arbitration panel had invalidated Hellebuyck's results from Oct. 1, 2001, to 2004, when he was banned for two years for testing positive for the banned performance enhancer EPO. At that time, he insisted he had not used performance-enhancing drugs.

But in 2010, Hellebuyck acknowledged using EPO since 2001. Based on that and other information, the panel last week ruled that all of his competition results dating back to October 2001 should also be disqualified. The panel rejected Hellebuyck's argument that the statute of limitations should safeguard those results.

"They were able to prosecute him for something that took place in 2001, in 2012," Howman said. "The statute of limitations is there, but the interpretation of how it works depends on the facts of each individual case."

Fahey added: "Circumstances may exist that allow the rule to be set aside."

"If there is a cheat out there, I'm very disappointed if that cheat is going to get away with it. I don't say that in respect of Lance Armstrong or anyone else. But, generically, I don't want cheats to succeed," Fahey said.

In the Armstrong probe, "we will never know in the criminal sense of what might have eventuated because they have dropped the criminal proceedings" he added. "Who knows, though, what might still be there."