The head of the IRS brushed aside accusations Monday that the agency has obstructed investigations into the targeting of tea party and other political groups, even as Republican lawmakers questioned his credibility.
Commissioner John Koskinen appeared at a rare evening hearing on Capitol Hill to answer questions about lost emails by a key figure in the probe.
"I know tonight will be difficult, and it deserves to be difficult for both sides," said Rep. Darrell E. Issa, California Republican and chairman of the House Oversight and Government Reform Committee. "We have a problem with you, and you have a problem with maintaining your credibility."
Mr. Issa accused Mr. Koskinen of misleading the oversight committee in the spring, when he promised to turn over Lois G. Lerner's emails. Since then, the Internal Revenue Service has disclosed that Ms. Lerner's computer crashed in 2011, losing an unknown number of those emails.
Mr. Koskinen said he first learned there was a problem with Ms. Lerner's computer in February, but didn't learn that emails were lost until April. The IRS notified Congress on June 13.
Ms. Lerner is the former head of the division that processes applications for tax-exempt status. The oversight committee is investigating the handling of applications from tea party and other political groups.
"I subpoenaed you here tonight because, frankly, I'm sick and tired of your game-playing in response to congressional oversight," Mr. Issa told Mr. Koskinen. "You, commissioner, are the president's hand-picked man to restore trust and accountability at the IRS. You testified under oath in March that you would produce all of Lois Lerner's emails subpoenaed by this committee.
"Mr. Commissioner, at a minimum you didn't tell the whole truth that you knew on that day," Mr. Issa added.
Mr. Koskinen said, "All the emails we have will be provided. I did not say I would provide you emails that disappeared. If you have a magical way for me to do that, I'd be happy to know about it."
He added, "I never said I would provide you emails we didn't have."
Mr. Koskinen said congressional investigators were informed months ago that Ms. Lerner had computer problems back in 2011. Mr. Koskinen said emails provided to the committee last fall showed that Ms. Lerner's computer had crashed.
"So it should be clear that no one has been keeping this information from Congress," he said.
In 2011, the IRS had a policy of backing up emails on computer tapes, but the tapes were recycled every six months, Mr. Koskinen said. He said Ms. Lerner's hard drive was recycled and presumably destroyed.
The IRS inspector general is investigating the lost emails, Mr. Koskinen said.
"It is not unusual for computers anywhere to fail, especially at the IRS in light of the aged equipment IRS employees often have to use in light of the continual cuts in its budget these past four years," Mr. Koskinen said. "Since Jan. 1 of this year, for example, over 2,000 employees have suffered hard drive crashes."
Ms. Lerner, who is now retired from the IRS, has refused to testify at two oversight committee hearings, invoking her right against self-incrimination.
The oversight committee is holding a second hearing on the lost emails Tuesday, which has sparked a back-and-forth with the White House. Mr. Issa invited an attorney in the White House counsel's office to testify, though the White House says her appearance isn't necessary.
Mr. Issa responded Monday evening by issuing a subpoena for Jennifer O'Connor, who worked at the IRS from May to November 2013, helping the agency gather documents related to congressional investigations and has since moved to the White House counsel's office.
Mr. Issa said he wanted to ask Ms. O'Connor about Ms. Lerner's lost emails. Late Monday, the White House said Ms. O'Connor would testify.