Check on the internet, THIS IS IDENTITY THEFT. You will have to jump through some hoops.
First, go online to the IRS, and get a form to report a fraudulent tax return.
Then you will have to file a police report - you must do this in person at your local police station. They have a form. After that, you will file your tax return by PAPER.
You will receive acknowledgement from the IRS, and your proper form will be filed. You will not be able to e-file for the year your tax return was "stolen".
