European news outlets and social media blew up this week after a parking warden in the German city of Karlsruhe issued a 30-euro parking ticket to an art installation of a truck bending itself up the wall of the city's famous technology and media museum.

The ticket was reported indignantly by a variety of European news outlets, and the warden was blasted online for being "pedantic" and "humorless" after pictures of the red Mercedes-Benz truck were published with the ticket tucked neatly under a windshield wiper — even though the truck is bent 90 degrees with its back half rising in the air.

The museum, the Zentrum für Kunst und Medientechnologie (Center for Art and Technology in Media), said it had persuaded the Oberbürgermeister, or mayor, of Karlsruhe to appeal the fine after it asked the artist, the Austrian conceptual sculptor Erwin Wurm, to pay it.

#zkmglobale Neues KFZ-Kennzeichen für den »Truck« mit eindeutigem Verweis auf Erwin Wurm! pic.twitter.com/BSzhIWCYQM — ZKM Karlsruhe (@zkmkarlsruhe) June 23, 2015

Commenters and art critics debated the meaning of the ticket. "It is only complete with the ticket. It shows that art is alive and real," one wrote on the museum's Facebook page, adding: "Without the ticket, the object would die."

"This is living art!" another wrote. A third remarked that Wurm was fortunate he wasn't "prosecuted for illegal vehicle modifications."

But the Berlin newspaper Der Tagesspiegel revealed the secret this week: "This was meant all along as a joke" as part of Karlsruhe's celebration of the 300th anniversary of the founding of Karlsruhe, a city spokesperson said. The warden printed a fake ticket in coordination with the city clerk's office, which then deleted it.

After the gag was blown, a spokeswoman for the museum told the newspaper: "We think it's great. It's good when the fine leaders of this city think for themselves artistically."