One radar almost doubles someone's speed limit. It turned out to be a duck and a “repeated criminal”.

Local authorities say radar images of speed offenders captured in central Switzerland last month show that the culprit is not only a duck, but may be a “repeated offender.”

The municipality said on its Facebook page over the weekend that they were surprised when they found the savages in the radar images taken on April 13 and found the puppets among people trapped in speed traps.

The post said the duck was caught in the 30km area to 52km per hour (32mph) and said the photos of fast birds.

The story was first reported by Berner Zeitung on Monday and even became stranger.

Facebook Post says it turns out that a duck with similar appearance was captured on the same date at the exact same speed. Officials called the duck a “notorious racer and repeat offender.”

Municipal authorities said it has considered whether the whole thing wasn't a belated April Fool's joke or a “fake” photo.

But the Police Inspection Department said it is impossible to do a doctor's or manipulate the radar system.

The municipal authorities explained that the Swiss Federal Institute of Metas (Metas) calibrates and tests the computers every year and seals the photos taken.

The Facebook post concluded: “We hope you enjoy thinking about curious coincidences, animal criminal activity and the maximum speed of flying for ducks.”