The California firm announced a June 7 start for its five-day Worldwide Developers Conference in San Francisco.

The annual event has become a stage for Apple to unveil software updates, particularly for iPhones that star in the company’s line-up of popular mobile gadgets.

Technology blog Gizmodo published details about the next iPhone earlier this month after getting its hands on a prototype of the device that it said was lost in a California beer garden by Apple software engineer Gray Powell.

“WWDC provides a unique opportunity for developers to work side-by-side with Apple engineers and interface designers to make their iPhone and iPad apps even better,” Apple senior vice president of iPhone software Scott Forstall said.

Mr Forstall promised that the conference will give developers in-depth sessions and hands-on labs focused on working with the latest generation operating system for iPhone smartphones.

The conference will also feature Apple’s first sessions for developers interested in tailoring programs for its freshly-released iPad tablet computer.

Analysts and industry insiders see the conference as a likely stage for Apple to introduce the upgraded iPhone 4G model and announce pricing and availablity.

According to Gizmodo, features of the new phone include a front-facing video camera for video chat, a flash and an improved regular camera with a larger lens.

It also has a flat back instead of curved back, is thinner than the 3GS, is three grams heavier and has a battery that is 16 percent larger.

Gizmodo is at the center of a police investigation into whether a crime was committed in obtaining the iPhone prototype, which has since been returned to Apple.

Police raided the home of Gizmodo editor Jason Chen last week and seized computer equipment in a hunt for evidence.

Gizmodo said it bought the iPhone prototype for $US5000 dollars from an unidentified person who found it in the bar where it had been left behind by Mr Powell.