Apple has reportedly placed orders for components that will be used in the next-generation iPhones.
The Wall Street Journal reports that component suppliers say that the new iPhone will be smaller and lighter than the iPhone 4 and will have an 8-megapixel camera.
The report cites "people familiar with the situation" and comes one day after Digitimes reported that the iPhone 5 had already gone into production.
WSJ reckons that Apple wants 25 million units by the end of the year but said that sources at Hon Hai, the company that assembles the iPhone, said that the new iPhone is complicated and difficult to put together.
The possibility that the next-generation iPhone would be thinner than the iPhone 4 has been raised before, with Apple reportedly investigating the possibility of making the SIM smaller - or even using an embedded SIM - in order to reduce the size of the device.
WSJ's report also claims that the new iPhones will use wireless baseband chips made by Qualcomm, rather than the Infineon chips used by the iPhone 4.