San Francisco police have assisted Apple in the search for a prototype of the latest iPhone that went astray in a bar in a repeat of an embarrassing loss that took place last year.

An Apple employee lost a yet-to-be-released iPhone 5 in a tequila bar in San Francisco's Mission District in July, technology news site CNET reported this week.

After the device was electronically tracked using GPS technology to a San Francisco house, four police officers and two Apple employees visited the home, the San Francisco police said in a statement distributed to news outlets.

"Apple employees called Mission police station directly, wanting assistance in tracking down a lost item," the press release said.

"The two Apple employees met with the resident and then went into the house to look for the lost item," it said. "The Apple employees did not find the lost item and left the house."

The statement did not identify the item being searched for but the title of the document carried a tantalizing hint: iPhone5.doc.

A resident of the home, Sergio Calderon, 22, told SF Weekly that he has visited the bar where the phone was reportedly lost but he did not have the device. He said the search of his house took place in July.

Cupertino, California-based Apple began selling the iPhone 4 last year and is expected to unveil the latest model, the iPhone 5, in September or October.

Word of another unreleased iPhone model disappearing in a bar came just weeks after prosecutors decided not to pursue criminal charges against Gizmodo technology bloggers who got hold of a lost iPhone 4 prototype last year.

Gizmodo published pictures and details of the iPhone prototype after buying it for $5,000 from a man who claimed to have found it in a beer garden where it was lost by an Apple software engineer.

Criminal charges have been filed against the man who purportedly found the iPhone 4 prototype and another who brokered the deal to sell it to Gizmodo.

The pair pleaded not guilty on Thursday to misdemeanor charges in San Mateo County Superior Court.