A web page listing the Vodafone Sure Signal, a product which boosts the carrier's network signal, included a list of compatible phones, including the mention of four types of "iPhone 5".
The page, which has now been amended, listed the iPhone 5 in four different models: 16GB black and white versions, along with 32GB black and white models.
The listing may have been a mistake, but the page also separately featured the iPhone 4, iPhone 3GS and iPhone 3G models.
Should the information prove accurate it would mean that the fifth iteration of the iPhone would not come in a 64GB model, despite the top end iPod Touch and iPads now boasting this level of flash storage.
However, it would suggest that Apple plans to offer the white version of the handset from launch, after problems in the production process resulted in a ten-month delay to the white iPhone 4.
There has been widespread speculation that the iPhone 5 will be released in October, after Bloomberg reported that US mobile carrier Sprint had revealed plans to sell the handset from next month. Separate reports have also indicated that staff at retail chain Best Buy have already been briefed for an October launch.
The iPhone 5 is expected to boast a raft of new features, including an eight megapixel camera and the custom-built A5 processor found in the iPad 2.
However, an analyst has claimed that Apple will resist the urge to increase the screen size of the forthcoming fifth iPhone to compete with the next generation of Android devices.