DigiTimes claims to have heard from an inside source that Chinese manufacturer Pegatron Technology has received a request to develop the handsets for a September launch.
The report appears to contradict claims that Apple will unveil the iPhone 5 at its Worldwide Developers Conference (WWDC) event in June. Based on past product launches, the firm is unlikely to release a new device three months after its announcement.
Pegatron Technology is also said to have received orders for a ten-inch iPad, ahead of its release at the end of this year. However, it is considered unlikely that Apple would sanction a tablet with marginally different proportions.
The rumoured iPad Mini is thought to be a more viable release for the Cupertino-based firm, with persistent rumours that Apple is planning to launch a budget tablet to take on the Kindle Fire.
Last month, it was reported that Apple's next iPhone will be partly made of an exotic new material called 'LiquidMetal'.