Ahead of what's expected to be Samsung Galaxy S3's official reveal on May 3, a sketch of the device has been leaked from what's probably a service manual. The manual shows what will apparently be the device's specs.

The sketch shows the traditional Galaxy S form factor that's seen in previous devices. It also shows a home button, but internals confirm the device will be running Ice Cream Sandwich (with TouchWiz likely on top). There's an eight megapixel camera, a 4.8-inch Super AMOLED screen, 1080p playback, the ability to record in 1080p and a 1.5 GHz Quad Core CPU. Considering Google is pushing for Ice Cream Sandwich devices to have software buttons, it may be a surprise that Samsung is bucking the trend.

On the front of the device there also seems to be a notification light which, according to rumors at least, could be for when the phone is charging.

Other features are a Gyroscope and a Barometer - the latter allows the device to gain weather information. There's no mention of GPS or NFC.

However, the 1.5 GHz CPU is a reason for one to be skeptical: on April 25, Samsung unveiled the rumored Exynos 1.4 GHz chip that's rumored to be in the S3 as Samsung moves from Qualcomm. Other rumors said the device will use a 12-megapixel camera, so the 8-megapixel camera could cast doubt on the manual.

Leaked photos suggested the S3 would support five rows of icons, like the Dell Streak, though that seems to be bogus when considering the leaked video of the phone and the previous device's form factors. The "S3' name was leaked in Kies, the software Samsung owners use to update devices. Two different versions numbers also appeared - the GT-i9300 and the GT-i9300T.

While the tipster's sources claim this could be an early draft, the Galaxy S2 manual doesn't include a page which runs down the specs in this way. Though if this is a draft, there's a chance the specs aren't final.

(reported by Jonathan Charles, edited by Dave Clark)