Blackberry's new flagship, currently codenamed Mercury, is set for a full unveiling at Mobile World Congress, following a preview at CES back in January. But if a leak from Twitter user @rquant is to be believed, the company will have a budget phone in tow as well, but before you get your hopes up, there could be a slight caveat.

The mysterious phone is currently codenamed BBC100-1 and features specs that firmly place it in the low-end category.

For starters there's said to be a 5.5-inch 720p display, Snapdragon 425 processor with 4GB RAM and 32GB of internal storage. Battery life could be quite good though, since there's expected to be a 3,000mAh battery, along with dual-SIM support, 13-megapixel and 8MP rear- and front-facing cameras respectively.

But, about that catch we mentioned. This potentially budget device is thought to Blackberry's joint BB Merah Putih venture. This venture, according to Venture Beat, has been set up in Indonesia and is said to be lead by PT Tiphone, which is an affiliate of Telkomsel, one of Indonesia's biggest mobile networks. 

BB Merah Putih will "source, distribute and market Blackberry devices in Indonesia". It will also have access to Blackberry's software and produce new devices locally in Indonesia. It's therefore possible that this new device, if real, will be reserved for Indonesia only.

With any luck we'll hear more information about the device at Mobile World Congress at the end of February.