Even as Sony has been preparing for the launch of its next flagship smartphone, Xperia Z5, sometime in September, a recent leak suggests that the Japanese tech giant is likely to unveil another variant dubbed as the Xperia Z5 Plus or Xperia Z5 Ultra alongside.

Christian Today reports that rumors suggest that the Xperia Z5 Plus/Ultra will feature a display screen with 4K resolution (3840 x 2160 pixels). Under the hood, the device will pack Qualcomm's Snapdragon 810 processor.

As of now, there is no information about the other specs and features for the Xperia Z5 Plus/Ultra, as the recent leak did not state anything else except for the phablet's screen resolution and processor.

It is expected that Sony will unveil the Xperia Z5 and the Xperia Z5 Compact at the IFA 2015 event that will take place in Berlin, Germany, from Sept. 4 to 9. However, currently there is no information about whether or not Sony plans to introduce the Xperia Z5 Plus/Ultra at the upcoming IFA event too.

Latest rumors hint that the Xperia Z5 will sport a 5.5-inch display screen with 1080 x 1920 pixel resolution. Under the hood, this smartphone will be powered by a Qualcomm Snapdragon 810 processor, alongside 3GB of RAM. Moreover, it is expected that the Xperia Z5 will come with a very sharp 20.7-megapixel rear-facing primary camera.

Meanwhile, Sony is also expected to launch another new smartphone, the Xperia M5, this month. The Xperia M5 will probably feature a 5.5-inch display screen with a 1080 x 1920 resolution, and will run on Mediatek MT6795 processor. It will have 3GB of RAM. Compared to the Xperia Z5, the Xperia M5 is expected to have a somewhat higher 21.5-megapixel rear camera.

In addition, there are rumors that another Sony handset, called the Xperia C5 Ultra, is currently in the works. However, no further information regarding this purported smartphone is available at this time.