Multiple people have come forward saying they were victimized in a check washing scheme linked to a post office in Merrick.

News 12 first reported about the issue Thursday after a man said his check was stolen after he dropped it into the mailbox on Fisher Avenue.

Several others also thought their checks would be secure because the mailbox only has a thin slot that someone wouldn't be able to reach inside.

Maureen McGovern placed four envelopes containing checks in one of the outdoor mailboxes in late September. All of the checks have disappeared.

One was washed and cashed for $2,700. Another was cashed for more than $7,000.

McGovern came forward after watching News 12 and seeing the same thing happened to somebody else.

"This is not isolated because it was the exact same location and the same story as mine so I thought the people in Merrick should know," McGovern says.

Another woman who called herself Sharon, also says she had checks stolen from the post office.

One of her checks was cashed for $6,800 and she still has not been reimbursed.

"I couldn't understand how it had happened because I mailed it from the post office," Sharon says

Mailboxes at the post office have thing slots meant to prevent thieves from stealing letters.

Law enforcement expert Denis Monette says criminals are still somehow getting them out.

"They found a way as they always do to maybe slide something in that little crack where the envelope goes in and it drops down," Monette says. "Maybe it's some kind of sticky substance on a string and then wiggle it back out."

The Nassau County Police Department says they are investigating several cases of check washing and they are working with the postal inspection service.

Police say anyone who suspects they were a victim of check washing to contact police.