The 26-year-old man was just about to throw out his rubbish when he noticed a plastic bag containing detailed drawings of the bank's security system, including floor thickness, movement detectors, doors, passageways and barred gates.
"I wanted to throw away my rubbish and I noticed the plastic bag with the building plans," the man told Bild.
Germany's central bank, Bundesbank, located in West Berlin's Charlottenburg district, opened just four weeks ago following renovation work which cost a total of $229 million.
"In the underground treasury room, several hundred million euros are stored beneath several meters of steel and concrete," the newspaper said.
Bundesbank spokesman Albrecht Sommer confirmed the find but made no further comment, adding all the drawings have been returned to the bank.