Whether it was a leak or one of those clever viral marketing campaigns, we’ll likely never know, but photos of the 2010 Toyota Prius have shown up online months before its planned unveiling at Detroit's North American International Auto Show in January.

First posted on Priuschat.com, a Web community for enthusiasts of the high mileage hybrid, the images have since been confirmed by Toyota to be the real deal.

• Click here for photos.

The design of the new Prius appears to be an evolution of the current model. It maintains the same basic shape, but trades some of its characteristic slab-sided and slope-nosed look for details that resemble other cars in the Toyota lineup like the Matrix and Corolla.

Toyota says the new car will be roomier and even better gas mileage than the one it replaces, but is keeping the exact specifications to itself until the official debut, or the next “leak.” It is widely believed to be getting a more powerful gasoline engine and electric motor to go with the increase in fuel efficiency. A plug-in hybrid version is expected to be added in later years.

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