The head of the House Oversight and Government Reform Committee has called on former Internal Revenue Service counsel Jennifer O’Connor to testify Tuesday about the disappearance of IRS mails that could shed light on the agency’s tea party controversy.

Rep. Darrell Issa (R-Calif.) issued the request in a letter to O’Connor, now a White House attorney, on Thursday. In the letter, Issa said that O’Connor “likely knew or should have known” that the IRS was missing years’ worth of e-mails to and from former agency official Lois Lerner, a central figure in the agency’s targeting of nonprofit advocacy groups based on their names and policy positions.

Rep. Darrell Issa (R-Calif.) – (AP/J. Scott Applewhite).

O’Connor, who began working for the White House this year, played a key role in supervising the review and production of records that congressional investigators requested as part of their review of the targeting matter, according to statements that IRS Chief Counsel William Wilkens gave to committee staff.

The White House did not respond to requests for comment about Issa’s letter or whether the administration plans to make O’Connor available for testimony.

The IRS notified Congress on Friday that it was missing e-mails for Lerner, who has refused to answer questions about the targeting controversy at two hearings. The IRS said her e-mails were lost after her computer crashed in June 2011 and that the agency subsequently destroyed her hard drive as a matter of protocol.

“A bad hard drive, like other broken information-technology equipment, is sent to a recycler as part of our regular process,” the agency said in a statement Thursday.

The IRS also said it plans to provide 24,000 additional Lerner e-mails from the 2009-2011 time period by searching the files of dozens of other individuals.

The agency has released e-mails confirming that Lerner’s computer crashed and that technology experts, including some from the IRS forensics lab, tried to recover the data.

“My computer skills are pretty basic, so nothing fancy — but there were some documents in the files that are irreplaceable,” Lerner wrote in July 2011 to an IT manager who offered to help her recapture the e-mails. “Whatever you can do to help is greatly appreciated.”

The manager later said: “I checked with the technician and he still has your drive. He wanted to exhaust all avenues to recover the data before sending it to the ‘hard drive cemetery.'”

IRS Commissioner John Koskinen is scheduled to testify about the lost e-mails before the House oversight committee on Tuesday, during the same hearing at which Issa has called on O’Connor to appear.