Ever since it was confirmed that Audi was developing the TT RS and especially after the Coupe made its public debut at last month's Geneva Motor Show, there have been rumors that the German automaker is developing an RS version of the A3. Well, this time is seems that the rumors were based on actual facts as our spy photographers snapped a test mule of the most powerful A3 performing test runs in Nurburgring, Germany.

Even though officially the RS3 has not yet received the green light, Audi's engineers have begun testing the TT RS's five-pot on an S3 mule meaning that the company is seriously considering a production version. For the record, it is not at all uncommon for automakers to test vehicles or specific versions of cars that are awaiting final approval for production. In the RS3's case, according to our sources, if all goes well and Audi's high-rank execs give their blessings, we could see the RS3 on the market as soon as 2010.

In the TT RS, the 2.5-liter turbocharged five-cylinder engine makes 340HP and 450 Nm (331.90 lb.-ft.) of torque. Most likely, those numbers will not change on the RS3 that will also get the TT's new six-speed manual transmission as well as Audi's quattro permanent all-wheel drive system.

Since the RS3 will probably weigh in about as much as the TT RS, expect to see similar performance figures with 0–100km/h (62mph) times of under 5.0 seconds and an electronically limited top speed of 250km/h or 155 mph. As with the TT RS, Audi will probably offer to remove the limiter as an option increasing the hot hatch's top speed to over 270km/h (170mph).

As for aesthetics, despite the fact that the only visible difference on the test mule were the covered foglights, the production RS3 will get the usual upgrades such as new alloy wheels, revised bumpers and front grille as well as a larger roof spoiler.