BMW's hotly anticipated M2 Competition has been leaked online via the brand's Australian website, confirming that it will use a 405bhp version of the brand's S55 twin-turbocharged straight-six engine.

The unit, which is also used in the M3 and M4 (where it offers 425bhp), replaces the regular M2's N55 engine to send a significant 40bhp more to the rear wheels and enable a 0-62mph sprint time of 4.2sec.

That's a tenth of a second quicker than the standard M2, but the M2 Competition will be even more impressive once rolling thanks to its 406lb ft of torque, representing a jump of 37lb ft. The N55 unit redlines at 7600rpm, suggesting the new car will also respond more eagerly to being revved out.

Along with its power boost, the M2 Competition also comes with an M Sport exhaust system that can be adjusted through several modes, as well as new chassis settings to offer sharper handling. These new features are accompanied by small aesthetic changes, including new wheels and different M seats inside.

Although there's still no official line from BMW on this hotter M2 model, the leak, which has since been taken down, suggests an official reveal is due imminently. The M2 Competition's arrival comes as no surprise; spy pictures of a development car had spurred on speculation that an S55-powered M2 was heading our way as early as last summer.

Autocar understands that the M division opted to use the newer 3.0-litre S55 engine in the M2 Competition because it provides enhanced performance while remaining largely under-stressed. The older N55 engine is thought to have been running close to its highest reliable output.

Despite the switch of engine, the M2 Competition's character is expected to be largely similar to that of the regular version, only with more focus. It's due with a six-speed manual or seven-speed DCT dual-clutch automatic gearbox. Although the latter enables the car's headline performance figures, market demand for driver-focused cars has ensured the manual remains the standard option.