The authorities in San Mateo County in California are considering whether to file criminal charges in connection with the sale of a missing next-generation iPhone belonging to Apple.

The San Mateo district attorney could act by early next week, according to people involved in the investigation. The office has the option of filing felony charges.

According to California law, if property doesn’t exceed $950, a case will be classified as a misdemeanor, but since the technology blog Gizmodo paid $5,000 for the device, a felony charge would be possible.

On Monday photographs and video of a possible next-generation iPhone, which is expected to be announced in June,appeared on Gizmodo.com. After some speculation about the authenticity of the iPhone, Apple’s legal counsel sent Gizmodo a letter asking that the device be returned. The letter stated: “It has come to our attention that GIZMODO is currently in possession of a device that belongs to Apple.”

Brian Lam, Gizmodo’s editor, said the organization had returned the device and that Gizmodo “didn’t know this was stolen when we bought it.”

In a New York Times article on Tuesday, Nick Denton, chief executive of Gawker Media, which owns Gizmodo, explained over instant message that Gizmodo paid $5,000 for the phone.

According to people familiar with the investigation,  who would not speak on the record because of the potential legal case, charges would most likely be filed against the person or people who sold the prototype iPhone, and possibly the buyer.

Gaby Darbyshire, Gawker’s chief operating officer, said in an e-mail message Friday that the organization had not been contacted by law enforcement officials, and declined to speak further on any legal aspects. Apple also declined to comment.

Stephen Wagstaffe, San Mateo County’s chief deputy district attorney, explained that “if there is any case that arises out of our office at this point the police have not submitted for prosecution.” He added: “We certainly know about what happened here in Redwood City” regarding the missing iPhone, “and we are the jurisdiction for any legal prosecutions” that could come out of the episode.

California law prohibits the sale of stolen goods and states that a person who uses someone else’s lost property without permission may be guilty of theft.

Mr. Wagstaffe said in cases like this it might not necessarily be a matter of lost versus stolen. In some instances of missing property, he said, “we call it misappropriation of lost property; it’s a crime but it’s not theft.” He added that “knowledge is a very important factor in a theft case.”

CNet reported on Friday that a task force, the Rapid Enforcement Allied Computer Team, had been investigating the case.

According to its Web site, the group is a computer task force made up of “17 local, state, and federal agencies, with the Santa Clara County District Attorney’s Office designated as the lead agency.” The purpose of the organization is to “arrest and prosecute a wide range of criminal offenders” related to high-tech business.

The Layar Augmented Reality Browser apps for the iPhone and Android provide virtual 3D information overlays on top of the real world, as seen from the camera lens of your mobile device. Today the company introduced a content store so that consumers can purchase additional layers of information to add to their dual-world experience.

At launch, the new content store includes paid layers from four partners that provides extra info to help app users better navigate the real world. The store is available now on all Android devices pending upgrade, and will be available as a part of its iPhone app in the near future.

Layar’s content store is designed to be friendly to both developers and consumers. Consumers can opt to buy these third-party-created layers in-app via Paypal and add additional content — think nearby food and beverage details, event info and venue-specific attractions — to their experience of the real world.

On the flip side, developers and publishers who use the content store to sell their data overlays will take home 60% of the net proceeds from sales. From the sound of it, publishers looking to profit by augmented reality are only limited by their creativity and their ability to provide content layers that consumers want to pay for.

As an example, launch partner Mouse Reality has made a $3.45 Disneyland layer that serves as a pocket and parent-friendly park guide with 2,700 points of interest, including shows, shops, dining options, rides and other attractions.

The content store is a certainly a smart way for Layar to stimulate interesting content development and profit by their augmented reality browser. What types of layers would you pay to add to your augmented reality browser? Share your thoughts in the comments.