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NSA leaker Edward Snowden may be entering a legal gray area as the U.S. and Russia continue to battle over his status as he whiles away the time at the Moscow airport.

WikiLeaks claimed on its Twitter page that a combination of factors -- namely, the revocation of his U.S. passport and an uncertain status with other countries -- could leave Snowden stuck in Moscow.

"Cancelling Snowden's passport and bullying intermediary countries may keep Snowden permanently in Russia. Not the brightest bunch at State," the group tweeted.

That scenario seems far-fetched. But at the least, his status poses a challenge to the diplomats and lawyers trying to handle his case on both sides.

State Department spokesman Patrick Ventrell -- asked repeatedly Wednesday about the possibility of Snowden being stuck in travel limbo -- told reporters that one possibility is the U.S. could issue him a document that allows him to take a one-way flight back to the U.S.

"That's the kind of travel document we're prepared to issue an individual accused of serious crimes," he said, adding that U.S. officials continue to make the case to the Russians that "there's a basis" for his return to the U.S.

He confirmed, though, that Snowden cannot use his invalidated U.S. passport at this point for other visas. The one-way ticket option would likely require Russian cooperation.

While Snowden no longer has a valid U.S. passport, Russian media also reported he may be traveling in Russia on a temporary transit visa.

This creates more questions about his status. A representative with the Russian Embassy in Washington told Fox News that such visas are good for three days -- meaning, if he has one, it would expire on Wednesday. For a stay longer than three days, a traveler is supposed to obtain a tourist visa, something that's supposed to be sought before entering the country.

Snowden's case, however, is far from typical, and it's unclear whether officials would bend the rules to facilitate his movement. Russian media quoted sources as saying the revocation of his U.S. passport is what's really keeping him from moving on -- preventing him from buying a plane ticket or even leaving the airport and setting foot on Russian soil.

WikiLeaks has claimed, though, that Snowden has refugee documents that could allow him -- somehow -- to get to Ecuador, which is still mulling an asylum request, or some other country.

The U.S., meanwhile, continues to pressure Russian officials simply to turn him over to U.S. custody, citing charges brought against Snowden last week. President Vladimir Putin so far has refused, effectively arguing that Snowden is not Russia's problem.

The competing demands and rolling developments in the case paint a picture of a complicated diplomatic tussle with no easily discernible outcome. It has created an embarrassment for the Obama administration, but also challenged relations between the U.S. and other countries, not just Russia.

The U.S. government already was fuming over Hong Kong's decision to let Snowden leave their jurisdiction over the weekend on the flight for Moscow. Adding to the dispute, Hong Kong officials reportedly said Wednesday that the U.S. government listed Snowden's middle name wrong on documents they submitted.

According to The Associated Press, Justice Secretary Rimsky Yuen said U.S. documents used the middle name James or the initial J., though their own documents had his middle name as Joseph. He said that helped slow the processing of his arrest, which Snowden ultimately evaded.

However a Justice Department spokesperson said Wednesday, "that Hong Kong would ask for more information about his identity demonstrates that it was simply trying to create a pretext for not acting on the provisional arrest request."

A former senior intelligence official told Fox News on Sunday that the Russians could choose to hide behind the "transit" route rationale -- claiming Snowden was not formally processed by Russian customs and immigration, and therefore is not in their hands.

However, the intelligence official said Putin was well within his powers to detain Snowden "in transit," and a decision was evidently made not to do so.

Fox News' Catherine Herridge contributed to this report.