HTC's mystery smartphone, M4, which is touted as the mid-range sibling of the company's HTC One, is also reported to feature a metal based alloy exterior case.

Taiwanese technology website DigiTimes in contact with its source has revealed that HTC has exclusively chosen 'Catcher Technology' to supply metal-alloy chassis for its mid-range smartphone M4 with shipments expected to begin in June.

The source also claimed the HTC has decided to give the chassis orders solely to Catcher Technology in order to avoid the component shortage issue to crop up again.

According to reports, HTC expects to ship 700,000 in Q2, 2013, i.e., within one month of its launch in June.

The Taiwanese company as well as Catcher Technology are yet to react to the speculations.

Almost a couple of weeks ago, HTC M4 specs were leaked in to the web hinting that it would sport a 4.3-inch HD display and run on Android's latest mobile OS version 4.1.2 Jelly Bean powered by a dual-core processor.   

Here is a leaked spec list of speculated HTC M4:

Model HTC M4
Display 4.3-inch HD display with 720p(Pixel density: 341 pixel per inches)
OS Android v4.2.2 OS (Jelly Bean) along with HTC Sense 5.0 interface
Processor Dual-core processor with 1.2 GHz CPU speed(Qualcomm Snapdragon 400 MSM8930 series Chipset)
Memory 16GB
Camera Main: UltraPixel camera (with unknown pixel count)Front:1.6-megapixel camera
Add-on features Bluetooth version 4.0,Wi-Fi (802.11 a/b/g/n),GPS/GLONASS