Boardman police are investigating another report of an altered check, this time involving mail dropped off inside the post office.

The woman told officers Monday that information on a check she mailed in late December was altered and cashed for thousands of dollars.

The victim said she wrote a check for $300 to a credit card company on Dec. 22 and dropped it in the mail slot inside the Boardman Post Office. When she reviewed her bank statement on Jan. 2, she discovered the check had been changed to $3,700 and made payable to a stranger.

The fraudulent check was deposited using a mobile banking application. The victim told police she believes the suspect may be working for the post office because she dropped the mail inside the building rather than an outdoor box. Postal officials have not responded to a 21 News request for comment.

This latest report follows a string of similar thefts in the area. Just last week, a woman on Indianola Road reported that a 40-dollar check was intercepted and increased to nearly $4,350.

In March, a local couple reported a loss of more than 32,000 dollars after several of their checks were stolen and altered. In that case, one check for about 53 dollars was changed to more than 5,500 dollars. Another resident reported losing 2,000 dollars in early December after placing a check in her home mailbox.

Check washing is a method where criminals use household chemicals to erase the ink on the payment and dollar amount lines of a check. Once the original information is removed, the thief writes in a new name and a higher value.

The United States Postal Inspection Service recommends residents take steps to protect their mail, such as picking up mail from home boxes immediately and monitoring bank accounts frequently. Experts also suggest using gel pens with permanent ink, which is more difficult to remove with chemicals. While federal authorities typically advise handing mail directly to a carrier or dropping it inside a post office to avoid theft, the most recent victim in Boardman said she followed that advice and still fell victim to fraud.