Edward Snowden's bespectacled and goateed face was almost unavoidable in Hong Kong last week. It stared out from newsstands, banners and giant TV screens on shopping malls and office buildings after it became known that the admitted leaker of U.S. secrets was in town and in hiding.

Still, when the U.S. asked the semiautonomous Chinese city for Snowden's provisional arrest, its response was essentially this: Who exactly do you mean?

Justice Secretary Rimsky Yuen said Hong Kong officials weren't sure who to look for because the U.S. government got Snowden's middle name wrong in documents filed to back its arrest request.

He said Hong Kong immigration records listed Snowden's middle name as Joseph, but the U.S. government used the name James in some documents and referred to him only as Edward J. Snowden in others.

"These three names are not exactly the same. Therefore, we believed that there was a need to clarify," Yuen said Tuesday.

Yuen said U.S. authorities also failed to provide Snowden's passport number. He said officials received the arrest request on June 15 and sent a request June 21 for clarification. Two days later, Snowden flew to Moscow.

"Up until the moment of Snowden's departure, the very minute, the U.S. Department of Justice did not reply to our request for further information. Therefore, in our legal system, there is no legal basis for the requested provisional arrest warrant," Yuen said. In the absence of such a warrant, the "Hong Kong government has no legal basis for restricting or prohibiting Snowden leaving Hong Kong."

U.S. officials don't buy Hong Kong's explanation, and neither do some legal experts in the city.

"It's not like he's some mystery figure. He revealed himself on TV," said Hong Kong University law professor Simon Young. "The whole world knows what he looks like."

Young and Hong Kong-based extradition lawyer Michael Blanchflower said authorities are able to exercise their discretion and use other methods to identify fugitives, who often use aliases.

"It may be in some cases that the person's name or passport number are not known, but for instance you could have a physical description accompanied by a photograph," said Blanchflower.

The decision to let Snowden go has raised tensions between the U.S. and Hong Kong. U.S. officials suggested that Beijing had a hand in letting Snowden leave Hong Kong, a former British colony that is now a semiautonomous region with its own legal system. But Hong Kong leaders say they were following the city's rule of law in processing the U.S. request.

The U.S. Justice Department said the government gave Hong Kong all the information that was required under the terms of their extradition treaty.

"The fugitive's photos and videos were widely reported through multiple news outlets. 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 spokeswoman said on condition of anonymity under ground rules set by the department.

"It wasn't a pretext at all," Hong Kong leader Leung Chun-ying said Thursday. "We were just following the laws of Hong Kong."

Young, who specializes in criminal law, said that because of the "political sensitivities" involved in the case, authorities did not rush the case and had taken extra care.

"I think that the Hong Kong government was insisting on a fairly high standard of completeness, and that, I assume, is their practice. They know that our courts will look at these things very closely and they don't take shortcuts," he said.

Snowden, a former National Security Agency contractor and ex-CIA employee, disclosed the broad scope of two highly classified counterterror surveillance programs to two newspapers. The programs collect vast amounts of Americans' phone records and worldwide online data in the name of national security.

He was expected to seek asylum in Ecuador, but it's unclear where he was Thursday. Russian President Vladimir Putin said this week that Snowden was in the transit area of Moscow's main airport, but a horde of reporters have found no trace of him.

The anti-secrecy group WikiLeaks says one of its staffers is with Snowden, and said Wednesday on Twitter that he is well.