The Salvation Army Temple Corps Community Center in north Houston received two gold coins in one week from an anonymous benefactor.

The coins were dropped in Salvation Army red kettles outside of Sam's Club and Walmart, along with notes celebrating Jesus' birth.

The first coin, a 1985 Canadian $50 Maple Leaf, was discovered on December 1 at the Sam's Club at 5310 South Rice Avenue. It was wrapped inside a $1 bill along with a note that read: "A child is born, Jesus! Merry Christmas!"

The second coin was found two days later at the Walmart at 1118 Silber Rd. It was also wrapped in a $1 bill, and accompanied by the same message, the Cleveland Advocate reported.

A Detroit-area Salvation Army location was surprised to find a gold coin worth over $1,000 in one of its red kettles this week.

An unknown person dropped a 1980 South African Krugerrand into the kettle outside of a Kroger grocery store in in St Clair Shores. Salvation Army spokeswoman Andrea Kenski said the coin is worth $1,200 – "enough to help feed 10 hungry people a year, or help provide coats to keep 48 children warm this winter season."

Other gold coins have been spotted in red kettles across the country.

"St Clair Shores has now become part of a national mystery around anonymous donations of collectable gold coins," Kenski told the Associated Press in an email. "A handful of locations across the country have repeatedly received these gold coins – each valued over $1,000 – in the same red kettle each year."

The Red Kettle campaign is the oldest and largest fundraiser in the United States. Many are familiar with seeing a person in a Santa hat, or a complete Santa suit, ringing a bell in front of a red kettle during the holidays.

The Salvation Army reminded potential donors that they also accept donations through the web.

@Outside of donating to the kettles outside of stores, those interested in supporting The Salvation Army this Christmas season can also do so virtually," a statement from the organisation read.

"We welcome groups and individuals to start their own online red kettle at OnlineRedKettle.org. "Here, you can set up your own virtual kettle and encourage your family, friends, and coworkers to donate to online."