The two men and a woman were held by police after a routine check showed their car had been registered stolen in Britain. The gang they are thought to be part of has been operating in the UK, Sweden, France and the Czech Republic, stealing the rhino horns probably for sale in East Asia where they can be sold for up to €50,000 each.

The Süddeutsche Zeitung reported on Sunday that the trio were suspected of robbing the horns from a stuffed rhino head in a museum in the southern German town of Offenburg.

The paper said a couple distracted the museum’s employees while two men upstairs climbed on top of a display case, took the head from where it was hanging on the wall and knocked its horns off with a sledge hammer. They then fled with the horns hidden in their coats.

It is not the first such incident. Norbert Niedernostheide of the German Museums Association told the paper there had been more than ten cases of rhino horn theft from museums, auction houses and zoos in the past year alone. Horns have been stolen in Hamburg, Münster, Bamberg and the eastern town of Sebnitz.

The illegal trade in rhino horns – which has fuelled poaching of the protected animals in the wild as well as attacks on living specimens in zoos – depends on the belief in parts of East Asia that they help make men sexually potent.

But Niedernostheide said this was probably rubbish. “The horns are made of keratin,” he told the Süddeutsche Zeitung. “You could also chew your fingernails.”

Despite the arrests, Niedernostheide warned museums to stay alert. “I think that the people behind the crimes will certainly continue,” he said.

The Local/bk