WASHINGTON — 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 e-mails by a key figure in the probe. On Tuesday, the committee will hear from a White House official, Jennifer O'Connor, who once worked at the IRS.
‘‘I know tonight will be difficult, and it deserves to be difficult for both sides,’’ said Representative Darrell Issa, a California Republican who chairs the House Oversight Committee.
Issa accused Koskinen of misleading the Oversight Committee in the spring, when he promised to turn over Lois Lerner’s e-mails. Since then, the IRS has disclosed that Lerner’s computer crashed in 2011, losing an unknown number of those e-mails.
‘‘We have a problem with you, and you have a problem with maintaining your credibility,’’ Issa said.
Koskinen said he learned there was a problem with Lerner’s computer in February but did not learn that e-mails were lost until April. The IRS notified Congress June 13.
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,’’ Issa told 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 e-mails subpoenaed by this committee.’’
‘‘Mr. Commissioner, at a minimum you didn’t tell the whole truth that you knew on that day,’’ Issa added.
Koskinen replied, ‘‘All the e-mails we have will be provided. I did not say I would provide you e-mails 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 e-mails we didn’t have.’’
Koskinen said congressional investigators were informed months ago that Lerner had computer problems in 2011. Koskinen said e-mails provided to the committee last fall showed Lerner’s computer had crashed. The e-mails indicate that Lerner had lost data, though they do not explicitly say Lerner’s e-mails were lost.
‘‘So it should be clear that no one has been keeping this information from Congress,’’ Koskinen said.
In 2011, the IRS had a policy of backing up e-mails on computer tapes, but the tapes were recycled every six months, Koskinen said. Lerner’s hard drive was recycled and presumably destroyed, he said.
The IRS inspector general is investigating the lost e-mails, 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,’’ Koskinen said. ‘‘Since Jan. 1 of this year, for example, over 2,000 employees have suffered hard-drive crashes.’’
The IRS was able to generate 24,000 Lerner e-mails from 2009 to 2011 because she had copied in other IRS employees.