You'd think that after last year's incident of the lost iPhone 4 prototype that Apple would take steps to make sure there was no repeat of the incident, right?

Well, according to Cnet, whatever measures were put in place they may not have been enough as another prototype of an unreleased iPhone is on the loose.

This time, the prototype appears to have been lost or stolen in a Mexican bar and restaurant in San Francisco in late July. It may have been sold on Craigslist for $200, the report says, though there are no details about the construction of the device or what OS it was running.

What is clear, though, was Apple's desperation to get the prototype back. According to Cnet's source, Apple contacted San Francisco police in an attempt to secure the safe return of the "priceless" prototype.

The phone was traced electronically to a nearby flat, which was swiftly paid a visit by police and Apple investigators. A man in his twenties admitted being at Cava 22, the bar where the prototype was lost, on the night in question but denied all knowledge of the phone.

Apple reportedly offered him money to return the handset no questions asked, the report said, but the man still denied any knowledge. A search of the property uncovered nothing.

There the trail goes cold, it seems. The bar owner told Cnet that he was aware of being contacted repeatedly about a lost iPhone, but had not seen the device in question.

Last month, a California county district attorney's office decided not to press charges against Gizmodo or former editor Jason Chen for the blog's part in a 2010 case involving a lost Apple iPhone 4 prototype. Instead, Brian Hogan, 22, of Redwood City, and Safe Wallower, 28, of Emeryville, were accused of misappropriation of lost property, and in Wallower's case, also with possession of stolen property.