House Republicans on Tuesday said the faulty hard drive of former Internal Revenue Service official Lois Lerner was less damaged than the agency let on and that backup tapes containing her missing e-mails may still be available.

GOP lawmakers are likely to raise the issues on Wednesday at a hearing with IRS Commissioner John Koskinen, who is scheduled to testify about issues related to the agency’s targeting of tax-exempt groups based on their names and policy positions. The hearing, which begins at 10 a.m., can be viewed live through the panel’s video feed.

“If the IRS would just come clean and tell Congress and the American people what really happened, we could put an end to this,” House Ways and Means Committee Chairman Dave Camp (R-Mich.) said in a statement on Tuesday. “Our investigators will not stop until we find the full truth.”

House Ways and Means Republicans said Tuesday that they learned that Lerner’s hard drive was only “scratched” and that the data was recoverable. They said the Internal Revenue Service ignored in-house advice to seek outside help to retrieve the information.

IRS chief John Koskinen, left, speaks with House Oversight and Government Reform Committee Chairman Darrell Issa (R-Calif.), right. (Michael Reynolds/EPA).

Also on Tuesday, Republicans on the House oversight committee released testimony in which IRS Deputy Associate Chief Counsel Thomas Kane said the agency is no longer certain whether it recycled all of the backup tapes containing Lerner’s e-mails. He said the question of whether some of the tapes still exist is “an issue that is being looked at.”

Koskinen testified before Congress last month that Lerner’s missing communications could not be recovered because the IRS had erased and then recycled her hard drive after it crashed in June 2011.

MORE: Timeline of IRS’s missing e-mails

Ways and Means Republicans said documents from the IRS’s internal tracking system show that “Lerner’s computer was once described as ‘recovered.'” They said IRS IT employees told congressional investigators on Friday that they were “unable to confirm the accuracy of the documents or the meaning of the entry ‘recovered.'”

Stephen Manning, a top IT official for the IRS, said in a U.S. district court filing on Friday that the agency erased the hard drive and transferred it to a recycling contractor after rigorous attempts to recover the data failed.

Manning also said the IRS recently found the serial number for the hard drive through the company that supplied the apparatus. Investigators could use the number to track down the device if it has not been destroyed.

Ways and Means Republicans said Defense Department forensic experts have told them that most of the data on a scratched drive should be recoverable.

The court ordered the IRS to provide information about Lerner’s hard drive and the agency’s handling of it as part of a lawsuit from True the Vote, a nonprofit conservative group that the agency targeted for extra scrutiny.