A Chinese website claims to have obtained engineering blueprints of what seems to be the next iPhone 5, and these point to a larger screen as reported by a number of websites over the last month.
Idealschina reports that they "just got what appears to be mold engineering drawings for iPhone 5. These would be used by case designers to create plastic, TPU, aluminum, silicone and leather cases. A while back we hear rumors that iPhone 5 would have a curved back but these images show iPhone 5 with the same form factor as iPhone 4 but with an edge to edge screen."
We're quite dubious when it comes to rumours about an iPhone 5 with a bigger sdcreen and we've written in the past why it wouldn't be possible to go beyond 3.5-inch (say up to 4-inch) without changing a number of things.
As Macrumors mentions, Chinese manufacturers in often have access to design documents in order to get the production of accessories started early.
This proved to be a winning formula when it came to links as it was proven for the iPod Nano 4G and the just released iPad 2 although there have been some very unreliable rumours in the weeks leading to the launch itself early this month.