The German city of Trier is struggling to keep up with demand for 0-euro notes, bearing the face of its most famous son and communism's creator Karl Marx, and sold for 3 euros each as part of celebrations for his 200th birthday.

Marx's best known and most influential works are the Communist Manifesto, co-written with Friedrich Engels and released in 1848, and his caustic analysis of capitalism "Das Kapital" two decades later.

"The souvenir plays on Marx's criticism of capitalism and of course the 0-euro note fits perfectly with Marx as a motif," said Norbert Kaethler, managing director of Triers' tourism office.

He pointed out that Marx did not earn much from his theories and had to live in poverty for several years of his life.

Trier's tourism office said it had already sold 5,000 of the purple notes, which resemble genuine euros but are labelled "souvenir", and was printing 20,000 more.

They are on sale at the Porta Nigra, the southwestern German city's most famous landmark and one of the largest Roman gates north of the Alps.

Marx, who forecast that capitalism would be superseded by socialism, spent the first 17 years of his life in Trier.

The city is proud of its most famous resident though some Germans blame his ideas for the rise of Communist dictators in Russia, China and Cuba and the Cold War division of their country.

The city is making the most of his 200th birthday on May 5. Other memorabilia include a bearded Karl Marx rubber duck with an edition of Das Kapital tucked under one wing.

Trier is also unveiling a giant three-tonne bronze statue of Marx, a gift from the Chinese government, despite concerns from critics about China's alleged human rights abuses...!!!