The image reveals that the smartphone measures over 130mm and it features no hardware buttons, with all commands placed on screen.
This new information on the Galaxy S3 comes in contrast to recent reports that claimed the handset would have a 4.7-inch display, a physical Home button and two capacitive buttons.
In addition, the leak for what appears to be the manual for the S3, as reported by Sammobile, hinted at a 4.8-inch Super AMOLED display device powered by Android 4.0 (Ice Cream Sandwich).
The device is rumored to offer wireless charging technology and feature a secondary front-facing camera.
The Samsung Galaxy S3 is set to be released on May 3 in London.