AT&T, the official and exclusive iPhone provider in the United States, is now listing a second model of the iPhone in its online device database called "iPhone Black", AppleInsider has revealed.

The drop down option to select an "iPhone Black" model is clearly visible alongside the "iPhone" for existing AT&T customers and can be seen by those who are logged into their account on the operator's site, and choose to select or update their current handset.

The finding has led to speculation that this could be what the new iPhone will be called when it eventually launches - something which is hotly tipped for June.

There have been ongoing rumours that Apple's second-gen iPhone would have a black plastic shell as opposed to the aluminum one of the current model and this could be seen to give weight to this possibility.