House Oversight and Government Reform Committee Chairman Darrell Issa (R-Calif.) said Tuesday that he has new evidence indicating the IRS knew about Lois Lerner’s lost emails in early February, and that the IRS waited four months before telling Congress.

That conflicts with testimony from IRS officials, who have said over the last several weeks that they only became aware of possible problems in April, and told Congress in June when it became clear the emails were lost.

IRS Darrell Issa John Koskinen Lois Lerner House

Rep. Darrell Issa, R-Calif., the chairman of the House Oversight Committee, is asking again for a special prosecutor to investigate the IRS, after finding evidence that the IRS didn’t tell Congress for four months — not two months — about Lois Lerner’s lost emails. (AP Photo/J. Scott Applewhite)

Issa’s committee heard testimony last week from IRS Deputy Associate Chief Counsel Tom Kane, who said Catherine Duval, counselor to IRS Commissioner John Koskinen, noticed on February 2 that some emails seemed to be missing. According to Kane, it was confirmed on February 4 that Lerner’s hard drive had crashed

“It didn’t take us long to figure out that it was reported that there was a hard drive crash at or about the time that the discrepancy in the emails took place,” Kane testified, according to the committee.

In a Tuesday letter to Deputy Attorney General James Cole, Issa said that testimony shows the IRS knew much earlier than it has previously said about the lost emails, and that the IRS waited four months — not two months — before telling Congress.

Issa’s letter stopped short of saying Koskinen and others lied to Congress. But it did say neither Koskinen nor Duval told Congress about the missing emails.

“Despite this awareness, Commissioner Koskinen failed to mention any problems with Ms. Lerner’s emails during his March 26, 2014, testimony before the committee,” the letter said. “Likewise, Ms. Duval failed to mention any issues with the IRS producing all of Lois Lerner’s emails during a meeting with bipartisan committee staff on April 4, 2014.”

Issa did, however, call on the Department of Justice to establish a special prosecutor to probe the IRS for its reaction to the targeting scandal. House Republicans have been after Lois Lerner’s emails to discern her role in the decision to apply extra scrutiny to conservative groups seeking tax-exempt status.

“The IRS’s failure to disclose in a timely manner that it had destroyed evidence critical to congressional and criminal investigations is further reason that a special prosecutor is needed to thoroughly and independently investigate all facets of the IRS targeting,” he wrote.

So far, however, the Justice Department has not announced it would set up a special prosecutor, and many Republicans worry that one will not be established in order to protect various political officials at the IRS.

Read Issa’s letter here: