Pictures of the device have leaked online showing a change in design direction that will see the flagship phone adopt an even more high-end appearance.
A pair of photos posted on VR-Zone's Chinese site show a prototype of the phone's outer shell in a metallic blue colour.
The snaps reveal the cover is now a solid wraparound sheet of metal, rather than a front and back with a joining rim like the HTC One's "sandwich" style case.
The device's camera remains in the same location, however there's now an additional unexplained hole in the back of the phone shell approximately a centimetre above it.
Speculation suggests that - if HTC has decided to follow in the footsteps of the iPhone 5s and locate a fingerprint scanner on the phone - it might be positioned in the mystery hole, however it would be awkward to use in that location.
With the HTC One having shaken things up with a 4-Ultrapixel camera, another idea for the hole's use is as the location of a secondary camera, but that seems like an unnecessary addition.
In addition, it's rumoured the newest member of the HTC family will have a 5-5.2 inch screen with 2K resolution, a larger face than the 4.7 inches of the HTC One's 1920 x 1080 pixel LCD screen.
It's said to have 3GB of RAM and carry Sense 6 and will be powered by a Quacomm Snapdragon 800 processor.
The name HTC M8 will only remain during development, before an official name is announced. The HTC One was called the M7 until it's release.
There's no word yet when the new phone will be launched or its name, but it's likely to hits stores in 2014.
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