After rumors that Sony would unveil the Xperia Z4 at the upcoming IFA 2015 to be held between September 4-9, a series of leaked press images of the smartphone reveal that it could be released 'any time soon.'

Sony has been expected to launch the Xperia Z4 in April with a Qualcomm Snapdragon 810 chipset, 3GB RAM, 32GB onboard storage, 20.7MP rear camera, 5MP front-facing camera, and Android 5.0 or 5.1 Lollipop out of the box. There have been a slew of leaks showing purported official press renders and live images of the Xperia Z4.

Earlier, leaked benchmark test results of the Xperia Z4 had suggested that Sony's next flagship would sport a 5.1-inch 1080p display and powered by a 1.9GHz Snapdragon 810 octa-core chipset paired with 3GB of RAM. The Xperia Z4 would have 32GB of internal storage and sport a 20-megapixel rear sensor with LED flash, along with a 5-megapixel sensor front camera. According to the leaked benchmark test results, the Xperia Z4 would also be waterproof and dustproof, and run on Android 5.0.2 Lollipop, with a 3,420mAh battery powering the phone and various connectivity options such as Bluetooth, NFC, GPS and Wi-Fi support.

More recently, new documents had surfaced related to the Federal Communications Commission (FCC) certification of a mysterious Sony device codenamed PM-0780 with similar dimensions as the previous Xperia Z3.

Another set of leaked images claiming to be of the Xperia Z4 with the model number E6553 had revealed that the device would be powered by a Snapdragon 810 processor with 3GB of RAM, Adreno 430 GOPU, along with 32GB of storage and a 20.7-Megapixel camera – similar to the Xperia Z3. Instead of a Quad HD display, Sony was expected to equip the Xperia Z4 with a 5.1-inch full HD (1080p) capacitive touchscreen display.

Yet another batch of pictures posted on a French website showed a phone that looks remarkably similar to the Xperia Z3 and indicated that the Xperia Z4 would continue to have IP68 anti-dust and waterproof certifications, as the flap for covering the microUSB port was missing.

A new set of alleged official Xperia Z4 renders have leaked again, showing the device in black color and based on Sony's OmniBalance design language. Similar to the earlier leaked press renders, the latest images show the design of the Xperia Z4 matching that of its predecessor with no change or modification.

In the leaked renders, the speaker cutouts on the Xperia Z4 also appear similar to the Xperia Z2, though the front-facing camera and the proximity sensor are positioned differently from the Xperia Z3. The renders of the black Xperia Z4 reveal a glossy and shiny metal frame, as against a matte-finish metal frame in the Xperia Z3.

Along with the Xperia Z4, Sony is also expected to launch a couple of variants, including the Xperia Z4 Compact and Xperia Z4 Ultra