While Sony is set to officially reveal a number of new handsets at Mobile World Congress later this month, a new 4K Xperia - a successor to Xperia Z5 Premium - isn't thought to be among them.

A tweet from @Ricciolo, who's made some mobile-related revelations in the past, suggests that the new handset is unlikely to be publicly displayed at MWC; instead, it will only be shown off to select parties behind closed doors.

It's suspected that Samsung is the reason behind the delay. In addition to that 4K display, the new Xperia will likely carry some high-end tech, including Qualcomm's upcoming Snapdragon 835 processor. But, as reported last week, Samsung is hoarding the supply of these chips for its Galaxy S8 smartphone. No Android flagships launched before the S8's rumored April 14 release will carry the 835 SoC - both the LG G6 and HTC U Ultra, for example, are expected to feature a Snapdragon 821.

It seems Sony doesn't want to use the older chips in the Xperia, which is thought to be codenamed 'Yoshino', so it's holding back the phone's unveiling. The behind-closed-doors model at MWC will likely be a prototype that uses an older Snapdragon processor.

Assuming this is the case, expect the new Xperia to make its official debut sometime after the Galaxy S8, possibly during early summer. We'll have to wait until then to find out if the other rumors, such as its 6GB of RAM and Sony IMX400 camera sensor, turn out to be accurate.