A picture has popped up online of a smartphone under the designation Motorola XT1056 that some are saying is the mysterious next device from the Google-owned manufacturer, the Motorola X.

Having already popped up before in an FCC filing - under the similar name of XT1058 - the phone has allegedly been photographed as it was being tested on Sprint's 4G LTE network. It is believed, therefore, that this is a variant of the AT&T version of the X, dubbed XFON.

Previous speculation suggests that the Motorola X has a 4.7-inch display, and Phone Arena's source claims that the screen of the device pictured is around 4.5-/4.6-inches, but hadn't measured it exactly, so 4.7-inch still sounds about right. Other rumours also claim that the processor will be a 1.7GHz Snapdragon one, but there's no word on what type exactly or how many cores.

The display is rumoured to be 720p, while the phone is hinted to come with 2GB of RAM and 16GB of on-board storage. The previous FCC filing also pointed to fifth-generation, superfast Wi-Fi and NFC connectivity.

The source states that the battery is removable and that the sample seen came with Android 4.2.2.

Yesterday, another picture of what is believed to be the Motorola X appeared online; this one allegedly from official advertising.

It is thought the new phone will be officially announced on 1 August.