The car could produce up to 280 horsepower.

A mysterious Ford Focus prototype has been spied on the outskirts of the Nürburgring.

Looking virtually production ready, the prototype has been equipped with a new aerodynamics package which includes a front lip spoiler and canards on the front bumper.  The model also has red body stripes, red mirror caps, and stylish five-spoke alloy wheels.

Little else is known about the car but our spy photographer believes it could be a high-performance version of the Focus ST.  As he points out, Ford recently introduced the Fiesta ST200 at the Geneva Motor Show so there's precedent for an upgraded Focus ST.  The 100 horsepower gap between the Focus ST and Focus RS also leaves plenty of room for a performance-oriented model to slot between the two cars.

If our photographer is correct, the model could use an upgraded 2.0-liter four-cylinder EcoBoost engine that develops 270 or 280 hp.  If these numbers pan out, the car would likely be called the Focus ST270 or Focus ST280.

Besides the upgraded engine, the high-performance model could include a sportier cabin as well as a number of chassis and suspension tweaks.

Gallery: Ford Focus ST Plus spy photos