A passenger handed in the bag to police and inside officers found the owner's ID, along with the cash all in €500 notes, sealed in an envelope, police said in a statement on Tuesday.
Officers later telephoned the rucksack's owner, a 66-year-old Israeli man, and after he told police the exact contents of the rucksack and proved the cash sum belonged to his company, they returned the bag to him.
The man said he had been in Munich for work since last Tuesday and took the S-Bahn to the airport on Friday morning to fly home to Israel.
But he forgot the bag as he disembarked, realizing his mistake after the train had left.
The identity of the woman who gave in the fortune is unknown. She appeared to have been in a hurry and handed over the bag without comment, leaving no name, police said.
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