Australian blogger Sonny Dickson tweeted pictures of a pair of mock-ups purported to be 5.5-inch and 4.7-inch versions of the next generation iPhone 6.
Apple Insider reports the mock-ups likely were made by case manufacturers and may not really represent the final model.
Both mock-ups have rounded edges more akin to the iPad Mini than the current iPhone 5 and 5s with their sharper angles.
Apple Insider says the aspect ratios of the two versions are a near-perfect match, making it easier for app developers to upscale.
The only other real detail to be gleaned from the pictures is rear of the larger version appears to have an updated camera flash design, possibly integrating the dual-LED TrueTone flash of the 5s into a smaller package.