German police have confiscated what may be the world's fastest office chair.

Police say officers happened on the contraption — the work of two inventive 17-year-olds — in the western town of Gross-Zimmern on Saturday.

The pair had added a lawnmower engine, bicycle brakes and a metal frame to the revolving chair — making into a go-kart-like vehicle.

Police said in a statement Monday the inventors insisted they had only tested it over a few meters, but witnesses reported seeing it on several streets.

They are being investigated over a variety of possible offenses, including defying insurance regulations, driving without a license and violating registration requirements.

Police did not say what top speed the chair could reach.

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