A total of 1.81 million yen (£7,000) was found across 18 mailboxes in a Tokyo apartment.

"The money was in identical plain envelopes, which were unsealed and carried no names or messages," a police spokesperson said.

But far from being gratefully recieved, many residents were unsettled by the gifts and refused to pocket the money -- instead they called the authorities.

"Some people initially suspected they were fake bills. When they realised the bills were real, they reported them to us," the spokesman said.

Tokyo residents have also been spooked by a shower of money, with many refusing to touch the money.

Around 960,000 yen (£4,500) were seen falling front of a convenience store.

"We can just say the money came from the skies," a police spokesperson said.

"There were other passers-by outside and customers in the store but the incident caused no confusion.

"People thought it was too eerie to touch."

The largest mystery donation so far was in Kyoto, where a 67-year-old woman found an envelope containing 10 million yen (£45,000) in her mailbox.

Although one man came forward to claim he was the mystery philanthropist, he was later discredited as a fantasist.

For now, the identity of the mysterious benefactor remains shrouded in mystery.