Officials in western Japan are marvelling at the generosity of a mystery philanthropist who donated a $1.8 million (980 000 pound) lottery ticket to help victims of recent torrential rainstorms.

In an extremely rare display of charity, a winning lottery ticket good for a 200 million yen grand prize was mailed to the governor of Fukui prefecture on Friday with a note saying it was intended as a donation for rain victims.

?I am sending a lottery ticket that is blessed with luck hoping that it will be of some help to the people who had the misfortune of suffering damages,? the letter said. Hiroko Imatomi, a Fukui prefecture official who first spotted the mail, said the note convinced her the sender was sincere. ?It was a wonderful letter ... It was definitely not intended as a hoax or a joke,? she said.

The sender used a false name and local authorities have no way to find out who sent the winning ticket.