HTC One (M9)
Posted online a day before HTC's media event, the video shows two minutes of hands-on time with the One (M9)YouTube/Samia Lou

HTC's cat is well and truly out of the bag, as a hands-on video showing off the unannounced One (M9) smartphone appears online, just a day before the official unveiling.

Published on YouTube less than 24 hours before HTC is due to hold a press conference in Barcelona to announce the Android flagship, the video shows the One (M9) next to its predecessors, the One (M8) and One (M7).

The narrator says HTC has "just announced" the handset, suggesting the video was recorded at an embargoed pre-briefing for journalists to see the phone before it is announced, but has been published early.

Tallying with a smorgasbord of rumours and leaks to hit the web in recent weeks, the video shows a handset similar in design to the year-old M8, with an aluminium body and 5in screen. But where the M8 used a single colour, the M9 is silver on the back and gold on the sides.

Also different on the new phone is its power/screen lock button, which has been moved from the top to the right edge, making it easier to reach when using the phone one-handed.

HTC has done away with the Duo rear camera of the M8, claiming it can no longer fit the second lens inside the phone's slim body, due to the One (M9) having a 20-megapixel rear camera, much larger than the 4MP sensor in the older handset.

That 4MP 'Ultra pixel' sensor hasn't been consigned to the scrapheap just yet though, as HTC is now using it for the M9's front-facing camera, which should produce some excellent indoor and low-light selfies.

As with the M7 and M8, the new model gets HTC's dual, front-facing Boom Sound speakers either side of the screen, and the handset is believed to be powered by the new, 64-bit octa-core Snapdragon 810 processor.

Although yet to be leaked, HTC is thought to be working on a smartwatch which could finally see the light of day at Mobile World Congress

IBTimes UK is in Barcelona for Mobile World Congress, where HTC is set to formally announce the One (M9) on 1 March, just hours before Samsung hosts a media event to reveal the Galaxy S6 and S6 edge smartphones.