The Internal Revenue Service (IRS), which told Congressional investigators that it would produce emails to and from Lois Lerner, has now said that many of the messages are missing because of a computer crash.

Lerner is former director of the IRS exempt organizations unit, which evaluates applications from groups for tax-exempt status. She has been the focus of investigations by House Republicans into whether Tea Party and other conservative groups were unfairly targeted for denial of that status.

Now, the IRS says it’s unable to deliver emails between Lerner and those outside the IRS from January 2009 to April 2011. Included in that group are messages to and from the White House, the Federal Election Commission and other agencies, according to Accounting Today.

House Ways and Means Committee Chairman Dave Camp (R-Michigan) expressed outrage about the news. “The fact that I am just learning about this, over a year into the investigation, is completely unacceptable and now calls into question the credibility of the IRS’s response to Congressional inquiries,” Camp said in a statement. “There needs to be an immediate investigation and forensic audit by Department of Justice as well as the Inspector General.”

The IRS said Lerner’s computer had undergone analysis to try to recover the emails, but in the end the only messages they were able to produce were those that Lerner had copied to other IRS employees.

In 2013, Lerner was subpoenaed to testify before a House committee investigating the targeting of conservative groups. Aside from a short statement saying she had done nothing wrong, Lerner refused to testify, invoking her Fifth Amendment rights. The House subsequently voted to hold Lerner in contempt.

Among the groups that had applied for tax-exempt status as a “social welfare group” was Crossroads GPS, the Karl Rove-run organization that spent $71 million trying to defeat Democratic candidates during the 2012 election cycle.

-Steve Straehley

To Learn More:

IRS Lost 2 Years of Lois Lerner’s Emails with Outsiders (by Michael Cohn, Accounting Today)

IRS Lost Emails By Official In Tea Party Probe (By Stephen Ohlemacher, Associated Press)

Karl Rove’s Crossroads Non-Profit at the Heart of IRS Targeting and Election Commission Clashes (by Noel Brinkerhoff, AllGov)