A U.S. mobile phone retailer that sells software to unlock iPhones isn’t surprised that more than a million of them seem to have “disappeared.” And it thinks it knows where they are. Information Week reports.

“Wireless industry analysts have been investigating a mystery involving iPhones. The number of phones that Apple says it has shipped doesn’t match up with the number of iPhones that AT&T and other wireless carriers have activated.

In reporting quarterly earnings last week, Apple said it had shipped some 4 million iPhones, while AT&T said it had about 2 million iPhone customers as of the end of 2007, in its quarterly report. More than a million iPhones seem to be unaccounted for.

Online retailer Wireless Imports thinks many of them are in Hong Kong. Wireless Imports has 500 to 1,000 iPhones that it has shipped locked in their original boxes. A large chunk of those units were sent to Hong Kong to be redistributed elsewhere and unlocked by the owners. The retailer estimates that there are 100,000 to 200,000 iPhones floating around in Hong Kong alone.”