The video uploaded to YouTube shows the 48-year-old politician on the balcony of his Berlin flat after being challenged by FDP leader Christian Lindner to take part in the charity craze.
After thanking Lindner for the nomination, Özdemir empties a bucket of water over his head.
But sharp-eyed internet users spotted the distinctive leaves of a cannabis plant waving in the breeze beside him.
Contacted by the Westdeutsche Allgemeine Zeitung (WAZ), Özdemir said simply that “yes, it is a hemp plant.”
The Greens have long been in favour of legalizing cannabis.
“If someone wants to consume cannabis and take the risks that go with it, a citizen should be able to decide that for himself in a free society,” Özdemir continued. “[But] no cannabis for under-18s,” he hastened to add.
Özdemir intended his video as a “gentle political statement,” but may have exposed himself to legal consequences. Only hemp that can't be smoked as a drug is allowed to be grown in Germany and the plant still has to be reported to authorities.
“We look into every possible breach of the law,” a police spokesman told WAZ, although he wouldn't confirm that there were plans to investigate Özdemir.
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