TOKYO (AFP) - A mystery benefactor has left about 2,000 lottery tickets in an elevator and asked that flood victims get the proceeds from any winning stub, Japanese police said on Tuesday (Dec 29).

An elderly woman found the tickets - which would have cost about 600,000 yen (S$7,025) to buy - and notes from the anonymous donor stuffed in a paper bag at the city hall car park elevator in Tochigi, north of Tokyo.

This summer the area was devastated by massive rain-sparked floods, which killed seven people and destroyed thousands of homes.

"Please give the money to people suffering from the rain disaster if any of these tickets win," one of the notes said, according to police.

The bag was addressed to Tochigi's city office and its mayor.

The top prize in this year's annual New Year's Eve lottery to be drawn on Thursday could be about 1.0 billion yen.

Authorities plan to keep the tickets for the next five months to see if anyone steps forward to claim ownership.

It is unclear what will happen after that if any of the tickets prove to be a winner.