WASHINGTON — The Internal Revenue Service official at the center of the storm over the agency’s targeting of conservative groups told Congress today 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.”

Members of Congress have angrily complained that Lerner and other high-ranking IRS officials did not tell lawmakers that conservative groups were targeted, even though legislators asked the IRS multiple times about it after local tea party groups told lawmakers they were being treated unfairly.

Lerner then said she would invoke her constitutional right to avoid incriminating herself.

“One of the basic functions of the Fifth Amendment is to protect innocent individuals, and that is the protection I am invoking today,” she said.

After Oversight committee Chairman Darrell Issa, R-Calif., asked her to reconsider, she said, “I will not answer any questions or testify about the subject matter of this committee’s meeting.”

Nine minutes after she began speaking, Issa excused Lerner but said she might be recalled.