A former postal worker in Fort Payne, Ala., is under investigation for allegedly stealing mail while on a route, officials said.

After customers began complaining about missing mail in mid-August, U.S. Postal Service office officials began to investigate, said Fort Payne Postmaster Mary Jo Crabtree.

"The matter has been contained," Ms. Crabtree said, explaining that the person suspected of the crime no longer is a postal service employee.

While Ms. Crabtree would not specify what type of mail was stolen, she told the Times Journal, Fort Payne's newspaper, that the postal worker targeted birthday cards. Get-well and anniversary cards also were reported missing, she said.

The U.S. Postal Service Office of the Inspector General is investigating the reports, and customers who had mail stolen soon will be contacted by agents from that office, Ms. Crabtree said in a statement.

The Office of Inspector General confirmed it is conducting a full investigation.

"We do take these matters seriously," office spokeswoman Agapi Doulaveris said.