LAFAYETTE, Ind. — A federal agency is trying to determine who's been tucking slips of paper into a portrait of President Obama in a federal building in Lafayette that call for the president's impeachment.

For several weeks, someone has been tucking slips of paper from anti-Obama pamphlets into the corner of a framed portrait of Obama that hangs in the Charles A. Halleck Federal Building in downtown Lafayette. Those messages haven't damaged the president's portrait but they do contain the phrase “Impeach Obama.”

A spokeswoman for the U.S. General Services Administration, which owns and manages the building, says the agency is investigating the tampering with the presidential portrait.

GSA spokesman Gina Blyther Gilliam says agency “does not tolerate this type of behavior.”