WASHINGTON (AP) — The Internal Revenue Service official at the center of the storm over the agency's targeting of conservative groups told Congress on Wednesday that she had done nothing wrong in the episode, and then invoked her constitutional right to refuse to answer lawmakers' questions.

In one of the most electric moments since the IRS controversy erupted nearly two weeks ago, Lois Lerner defended herself during a brief appearance before the House Oversight and Government Reform Committee. The committee is investigating the agency's improper targeting of tea party and other conservative groups seeking tax-exempt status from 2010 to 2012, and Lerner oversees the IRS office that processes applications for that designation.

"I have done nothing wrong," said a stern-looking Lerner, sitting next to three other witnesses and reading from a written statement. "I have not broken any laws. I have not violated any IRS rules or regulations and I have not provided false information to this or any other committee."