Photo: Contributed

Vienna's transport authority says a city bus driver checking a bag left behind by a passenger had the surprise of his life, a $500,000 surprise, in neatly stacked 500-euro bills.

Transit authority spokeswoman Anna-Maria Reich says the driver handed the stash to police who tracked down the owner, an unidentified elderly woman.

But the driver has nothing to show for his honesty beyond praise from superiors. Weeks later, the owner has not contacted him to offer a reward.

The incident happened last month and Reich confirmed details first reported Thursday by several Austrian tabloids. It was unclear why the woman was carrying so much cash.