Sony recently launched three models of the Xperia Z5 (the standard, Premium, and Compact), but a new report has claimed that a fourth model is coming. It's actually a higher-spec'd variant of the Compact.

According to Chinese website CNBeta, Sony plans to upgrade the Compact's specs by releasing an entirely new version in Japan. The current Compact has a 4.6-inch 720p screen, 1.5 GHz quad-core Snapdragon 810 chipset, 2GB of RAM, 32GB of storage, 23- and 5.1-megapixel cameras, and a 2700mAh battery.

The new Compact, called the Xperia Z5 Compact Premium, naturally, will reportedly be available to purchase by next month. It'll feature a 4.6-inch Full HD display, 4GB of RAM, and a 2900mAh battery, along with the same chipset and cameras found in the standard Compact.

The Compact Premium will therefore be more powerful and longer-lasting than the standard Compact. It'll also have that crisper 1080p display - which is something we think most smartphones should launch with anyway.

To corroborate its report, CNBeta posted a leaked press image for the handset (above), which showed the backplate covered in Hatsune Niku branding, suggesting the Compact Premium will likely be exclusive to Japanese carrier DoCoMo. No pricing or release date details were revealed.

Most reports think Sony will launch the Xperia Z5 Compact Premium soon. We'll keep you posted.