MINNEAPOLIS (WCCO) — Rep. Michele Bachmann is joining the calls for a thorough investigation as President Obama prepares to answer further questions about the growing controversy at the IRS.

The acting commissioner resigned on Wednesday after the agency admitted it targeted conservative groups for tougher scrutiny.

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Bachmann has somewhat of a personal interest in the story. The IRS apologized for targeting conservative groups including the Tea Party. Bachmann is the chairwoman of the Congressional Tea Party Caucus.

On Thursday morning, Bachmann held a press conference in Washington D.C. flanked by dozens of her congressional colleagues and members of the Tea Party movement.

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All spoke out about the reported misconduct that started in 2010 at an IRS office in Cincinnati, where they began screening applications using the search words “Tea Party”, “9/12” and “Patriot.”

Bachmann is calling for an investigation to find out if the White House knew that conservative groups were targeted.

“This is the question Americans want to know. This is what all the Tea Party leaders behind me want to know, as well as members of Congress,” she said. “What was it that the White House knew? …  Were they involved in the directives?”

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The Federal Bureau of Investigation is involved in the case. Investigators will also look into whether the civil rights of conservative groups were violated.