Ahead of its May 3 reveal in London, a leaked photo of the Samsung Galaxy S3 suggests the phone won't feature the much-rumored 12-megapixel camera. If that's true, as far as camera specs are concerned, Galaxy S3 may be no better than iPhone 4S and Apple could use this to its advantage when it launches iPhone 5.

The photo, originally from GSMArena, clearly shows the rear camera and the "8.0" megapixel label on a potentially aluminum back (though it looks textured at least), with the Galaxy S3 name on the back.

Previous leaks, such as the device supporting five-row icons, or being a Samsung Galaxy S2 "Plus," look to be bogus. The latest photo 'leak' looks very much real or else, it's a very convincing mockup.

While the photo of the camera doesn't show the front, a press photo surfaced from GSMArena.  The photo shows the rumored home button, but only two buttons on the front. The phone is expected to feature three, though reports said the device wouldn't use software buttons like the Samsung Galaxy Nexus. GSMArena confirmed the mockup was old, though, which explains the differences.

Know Your Mobile also uploaded a picture of what it claims is the device, and shows the display. It's turned off, but does show two physical buttons along with the home button. The back button on the right and the menu button on the left look different to the GSMArena image, suggesting this is the more recent version. There are no specs, but the display's size is reportedly as high as 4.7 or 4.8 inches.

Another picture from Know Your Mobile measures the phone against a ruler, showing the curved top-to-bottom design. The site claims the device has a 4.8-inch display.

Elsewhere, a 'leaked' service manual of the device said the S3 features a 4.8-inch display, though there's no word on internals or software. According to the manual, though, the phone will run Android 4.0 Ice Cream Sandwich - almost certainly with the TouchWiz skin - and use a 1.5GHz Quad Core CPU.

If GSMArena's photo leaks are genuine, Samsung could be in trouble because an 8-megapixel camera puts it at par with iPhone 4S' camera system. And, if iPhone 5 launches with a 10- or 12-megapixel camera, the sixth generation smartphone from Apple will loom over Samsung's latest offering. And, that won't look good for Samsung, as Galaxy S3 is the most-anticipated Android phone of 2012.

What do you think? Will Galaxy S3 feature 8-megapixel or 12-megapixel camera? How will it fare against iPhone 4S? Leave your comments below.

(reported by Jonathan Charles, edited by Dave Clark)