A filing with the Federal Communications Commission (FCC) in the US has poured further fuel on rumours surrounding the existence of the Motorola X Android smartphone.

Along with a diagram of the back of the device, the documents reveal that the XT 1058 - the model number listed - will work on AT&T's LTE bands for 4G data, have 802.11ac wireless internet technology, and NFC. The 802.11ac Wi-Fi chip is of particular interest because that's the fifth generation of the wireless standard and therefore offers superfast connectivity.

It will also have Bluetooth, but you would be hard pressed to find a smartphone that doesn't.

Persistent tipster @evleaks revealed several pictures of, what was claimed to be, the Motorola X at the beginning of May. In those, the alleged handset was wrapped in a casing that could have been for shielding and testing purposes. Perhaps the tests conducted are those listed in the FCC filings.

Either way, we expect there to be more news on this handset and, we hope, possible worldwide variants at Google I/O this week.