Lufthansa flight attendants smuggling scrapped euro coins back from China and bringing them back into circulation

German police have uncovered a scandal involving Lufthansa flight attendants smuggling scrapped euro coins back from China and bringing them back into circulation, the Bild daily said Thursday.

In what the paper said was the biggest scandal involving euro coins, once back in Germany the cabin crew would then exchange the coins for notes at the Bundesbank central bank.

Police have carried out dawn raids at the Bundesbank and at firms in and around Frankfurt in western Germany including at Lufthansa, the country's flag carrier, Bild said, with six people taken into custody.

"They are under investigation for circulating false money," prosecutor Doris Moeller-Scheu told Bild.

Every year the Bundesbank takes out of circulation hundreds of tonnes of dirty, bent coins and breaks them into separate metals, which are then shipped to China.

Bild said the pieces were then re-assembled by criminal groups, which hired flight attendants to smuggle them back into Germany, creating losses for the eurozone of at least 20 million euros (28 million dollars).

Authorities were alerted after a Lufthansa stewardess was caught by customs officers with thousands of one-euro and two-euro coins in her bag, the paper added.