An inspector general’s office has retrieved tens of thousands of ex-IRS official Lois Lerner’s e-mails from a disaster recovery drive . (Pete Marovich/Bloomberg)

Many of Lois Lerner’s missing e-mails may no longer be missing.

The Treasury Inspector General for Tax Administration told several congressional committees on Friday that it has recovered as many as 30,000 of the ex-Internal Revenue Service official’s messages from disaster recovery tapes, according to congressional aides who participated in a briefing on the matter.

IRS Commissioner John Koskinen testified in June that the e-mails were lost after Lerner’s hard drive crashed in 2011. He said the agency tried unsuccessfully to retrieve the records with help from agency IT and forensic experts.

Koskinen acknowledged the existence of disaster recovery tapes but said the IRS didn’t try to retrieve Lerner’s e-mails from them because they only contained six months worth of data and because the process would have been extremely difficult, partly due to the amount of information on the tapes.

Inspectors have not yet determined how many of the e-mails were among those that the IRS has failed to produce for congressional investigators. Some of the recovered records might have been given to the oversight committee before, the staffers said.

The GOP-controlled House oversight and ways and means committees have sought the e-mails as part of their investigations into the IRS targeting scandal, which involved screening nonprofit advocacy groups for deeper review based on their names and policy positions. Most of the affected groups were conservative, although a small number of them were left-leaning.

Republicans have alleged that the Obama administration used the IRS and other enforcement agencies to silence conservative critics during the 2010 and 2012 election cycles, when the targeting occurred.

The missing e-mails cover a period from 2009 to 2011, when Lerner was head of the exempt-organizations division that selected the groups for extra scrutiny. Lerner, who retired months after acknowledging the agency’s inappropriate actions, has invoked her Fifth Amendment right at two separate congressional hearings on the matter.

House Oversight and Government Reform Committee Chairman Darrell Issa (R-Calif.) said in a statement on Friday that the recovered e-mails might contain “significant information.” He added that his panel will examine the e-mails for clues about Lerner’s “mindset and who she was communicating with outside the IRS during a critical period of time when the IRS was targeting conservative groups.”

The IRS said in a statement on Friday that it “remains committed to fully cooperating with all of the pending investigations.” The agency also said it has already sent more than 24,000 Lerner emails from the period before her hard drive crashed.

The inspector general’s office may need several more weeks to “decrypt” the files before sending them to the IRS for redactions, according to the aides.

The House and Senate committees on finance and ways and means may ask to view the e-mails as soon as they are ready for the IRS, since those panels have authority to view unredacted records containing sensitive taxpayer information.