Only four weeks ago, the bank’s building in western Berlin was officially opened after renovation work which cost about 150 million euros ($221 million).

The hairdresser found detailed drawings of the safety arrangements at the bank, including the location of people detectors, stairwells, grilled gates and measurements with the depth of the vault’s floor, reported top-selling newspaper Bild. "I wanted to throw away my rubbish and I noticed the plastic bag with the building sketches," Bild quoted the 26-year-old male hairdresser as saying. The bin was in a backyard in central Berlin.

A Bundesbank spokeswoman confirmed the Bild report, adding the bank was looking into how the plans could have ended up in a bin. She said she believed it would be impossible for anyone to break into the safety vault. The Bundesbank, which this year celebrates its 50th anniversary, is one of the pillar’s of Germany’s economic success since the end of World War Two. In 1999 it handed over its decision-making powers on interest rates to the European Central Bank whose independence was modeled on the Bundesbank.