BROOKLYN - An investigation by the federal government is under way to find out who is responsible for stealing checks from synagogue mailboxes and cashing them fraudulently.

The FBI says more than 15 synagogues have been defrauded around the nation. Most of the checks are stolen from donation mailboxes.

In one case, a check for $250 was altered and cashed for $1,250.

Officials at the Young Israel synagogue in Midwood realized the problem when they began billing their congregants twice before receiving membership dues.

Local synagogues are now securing their mailboxes and asking congregants to be deliver checks in person.