HTC is believed to be ready to release an upgraded version of its flagship phone - the HTC One - later this year or in early 2014. Sources close to the company have strongly suggested the next flagship model - codenamed HTC M8 - is already in the works.

According to Pocket Lint, HTC is using various codenames for the device while discussing the product with external contacts, in order to keep handset details under wraps and avoid product specification leaks ahead of launch. The leaked codename HTC M8 clearly suggests the successor to HTC One, aka HTC M7, is already in the making.

With Google's next iteration of the Android software - 4.3 Jelly Bean - under development, HTC is expected to make significant internal hardware changes, including possibly replacing the existing Snapdragon 600 chipset on the HTC One with the world's fastest smartphone processor - Qualcomm's Snapdragon 800.

The Sony Xperia Z Ultra is the first smartphone to ship with this processor.

Last year, the HTC One X met a similar fate, with a revamped Sense UI and an improved front-facing camera and a new chipset making its way into the upgraded HTC One X+.

If the past is any indication, the HTC One's successor is also expected to debut an affordable variant, with a plastic body, besides the regular model with unibody aluminium finish.

The HTC One was officially introduced earlier this year, with a powerful hardware configuration including a 4.7in Super LCD3 full HD display powered by a Qualcomm Snapdragon 600 chipset, based on a 1.7GHz quad-core Krait 300 processor paired with Adreno 320 GPU.

Other key specifications include 2GB of RAM, 32/64 GB storage variants (with no support for microSD expansion), a four megapixel UltraPixel sensor with autofocus and LED flash and a 2300mAh battery.

The HTC One is 9.3mm thick and weighs 140 grams. Its connectivity options include Wi-Fi 802.11 a/ac/b/g/n, Bluetooth v4.0 with A2DP, Near Field Communications (NFC), Infrared blaster and microUSB v2.0.

In addition to the rumoured HTC M8, the Taiwan-based phone maker is expected to unleash two more smartphones later this year, namely HTC One Mini and HTC One Max, with similar design and feature elements to its flagship phone.