SAN FRANCISCO - San Francisco's police chief says officers helped Apple Inc. investigators look for a missing iPhone prototype that was left in a city restaurant in July.

Police Chief Greg Suhr (SIR) told the San Francisco Chronicle that four officers accompanied two Apple investigators who searched a San Francisco home for the lost gadget.

Authorities say the Apple employees conducted the search after asking the resident's permission and the officers did not enter the home.

Officials say Apple used GPS technology to track the smartphone to the home, but it wasn't found there.

Apple officials have declined to comment on the case.

On Thursday, two men were charged with misdemeanours for selling a lost Apple iPhone 4 they found in a Redwood City, California, bar in March 2010.