CNET reports an Apple employee lost a prototype in late July in the Cava 22 tequila lounge in San Francisco's Mission District.
Sources claim Apple electronically traced the phone to a home in the Bernal Heights neighborhood.
They say San Francisco police searched the house, accompanied by apple investigators, but found nothing.
Last year, an Apple employee lost an iPhone 4 prototype in a German beer garden in Redwood City. In that case prosecutors filed criminal charges against two men they say sold the phone to the Gizmodo blog.