Despite myriad reports all over the web of the touchscreen BlackBerry Thunder's specifications and likely network carriers, maker RIM is still refusing to officially confirm the handset's existence. When we spoke to RIM's press team this morning, we were yet again given a polite but firm "I'm afraid we can't comment on that" response.

The smartphone maker is currently rolling out its quad-band, 3.5G BlackBerry Bold 9000 handset to UK carriers and to their counterparts in other territories and is understandly keen for reviewers to focus their attention on the merits of that handset. The BlackBerry Bold is the first handset in the new 9000 range and sports a silver-accented new design.

The strongly rumoured Thunder, however, has partly stolen the thunder of the Bold simply because it's a touchscreen handset - ie the real iPhone killer.

Online reports at well-known mobile phone sites point to the BlackBerry Thunder having an iPhone-beating 460x320-pixel screen with 65,000 colours - this would make sense given that this is what's fitted on the Bold and RIM told us last week that its policy is to apply all innovations introduced on one generation of handset and carry them forward to successive models.

On that basis we also expect the Thunder to have HSDPA 3.5G connectivity, Wi-Fi, Bluetooth v2 with A2DP, a 2Mp camera with flash and a 3x zoom, at least 1GB of storage (with support for up to 16GB) and assisted GPS.

If reports prove true, the BlackBerry Thunder will engage in battle royale with the iPhone 3G from October - in the US, at least, where carriers are rumoured to be Verizon and Vodafone.

Earlier this week, details of still more BlackBerry handsets hit the web, including more shots of the first clamshell BlackBerry and an iPhone-esque BlackBerry Javelin.

Click here for our review of the RIM BlackBerrry Bold 900 smartphone.