An official certification leak in China suggests that this year's Mobile World Congress in February could be big for Microsoft. It suggests a new phone is on its way from the corporation and it is likely to sit in the higher mid-range.

Common thought is that the RM-1182 - as it appears in the certification document - is either the previously rumoured Microsoft Lumia 750 or even a Lumia 850.

The certification is dated 28 December and that suggests that it is likely to make an appearance in Q1 this year - with Mobile World Congress conveniently timed for an official announcement.

There are few other details to be gleaned from the leaked document other than the fact the device does not feature fast charging. But if genuine, it will definitely be ranged by China Unicom, a state-owned network in the country.

Previous rumours had actually suggested that both the 750 and 850 could be announced during the next couple of months, with the Lumia 750 featuring a Snapdragon 617 processor, 2GB of RAM, 16GB of storage and either a 5.4-inch or 5.7-inch Full HD screen. No details on possible specifications for the Lumia 850 have hit the net as yet.

Pocket-lint will be attending Mobile World Congress and will report on any Microsoft activity then. In the meantime, you can keep an eye on our rumour-round up preview feature here.