UPDATE: The SFPD responds to reports about the missing prototype.

ORIGINAL ARTICLE: At this moment it’s possible that an upcoming iPhone, possibly the iPhone 5, might be hanging out in the unswept corners of a Mexican restaurant. Or it might be in the hands of someone ready to make a big score.

Or the prototype might not be lost at all. Such is the rub when it comes to single sources.

According to CNET, an Apple employee misplaced the unreleased iPhone at Cava 22, a “tequila lounge” in San Francisco’s Mission district. The source indicated that the iPhone might have been sold on Craigslist for 200 bucks.

CNET has more details on how Apple reacted to the loss of their prototype. Apparently, once the unnamed employee manned up the courage to tell his bosses what he had done, Apple contacted the San Francisco Police Department. Apple electronically traced the iPhone to a “two-floor single family home” in the Bernal Heights neighborhood. With the help of the SFPD, Apple’s investigators went to the house.

A twenty-something opened the door and acknowledged being at Cava 22 on the night in question but denied knowing anything about an iPhone prototype. He allowed police to search his house but they came up empty. According to the source, Apple offered the man money for the device, but he stuck with his story.

If this all sounds somewhat familiar, that’s because this has happened before – under almost identical circumstances.” Last year, an Apple software engineer lost the iPhone 4 prototype in a German beer garden in Redwood, California. That prototype ended up falling into the hands of Gizmodo, who leaked all the juicy new details of the device.

If this whole thing is true, nobody’s saying anything about it. Apple, Craigslist and the SFPD are all keeping quiet. The owner of Cava 22 has said that he remembers a guy calling multiple times about a lost iPhone. But who really knows if that had anything to do with this prototype? I’m sure plenty of people have too much tequila and misplace their mobile device.

Did all of this really happen? Is there a prototype of the iPhone 5 out there somewhere? Maybe. I mean, it has happened before. If the secret phone was obtained sometime in July, however, it is kind of strange that nobody has come forward with it yet. The time to cash in on the find might be coming to a close. Most reports put the iPhone 5 release sometime in October.