Apple’s much-rumored iPhone 4G is expected to be disclosed at Worldwide Developers Conference which will take place in June in San Francisco.

Apple chief executive Steve Jobs will address developers on June 7 and Apple is known for its tradition of introducing its new products at the conference.

Apple’ iPhone 3G was introduced at last year's Worldwide Developers Conference and the product was put for sale in less than two weeks following the conference.

Apple’s iPhone 4G was gained attention after a prototype of the device was found from a bar in San Francisco. Tech blog called Gizmodo revealed the features of the device after it bought it from an unidentified person for $5,000.

It was cleverly disguised in an iPhone 3G case. But, unlike 3G it had two cameras, a front-facing video camera plus a rear camera with flash. Device’s touchscreen had an estimated 960 x 640-pixel as compared with 480x320 pixels in 3G.

The prototype suggested that the upcoming iPhone 4G would be 116.8 by 58.6 by 0.93mm in size and 140g in weight. Prototype’s battery was larger than 3G’s, but battery life could not be known.

Apple is yet to announce the launch of its next-generation iPhone.