When San Francisco police and Apple’s investigators visited the house, they spoke with a man in his twenties who acknowledged being at Cava 22 on the night the device went missing. But he denied knowing anything about the phone. The man gave police permission to search the house, and they found nothing, the source said.

After last year’s embarrassing loss, Apple reportedly has taken extraordinary steps to protect its prototype devices from leaks. Next-generation iPhones are sent to carriers for testing “inside locked and sealed boxes so that the carriers can carry out checks on their network compatibility in their labs,” according to the Guardian.

Apple developers have been given new iPhones with an upgraded processor — the one that is used in the iPad 2 and is expected to appear in the next-generation iPhone. But the device “is virtually identical to the iPhone 4, and there is no way anyone can tell it’s not an iPhone 4 based on the phone’s exterior,” a report at 9to5Mac.com says.