Lerner was the IRS official at the center of allegations that the agency targeted tea party groups applying for nonprofit status. Congress requested Lerner’s emails from the IRS and agency officials told lawmakers an unknown number of emails had been lost when Lerner’s computer crashed.

The Treasury Inspector General for Tax Administration is in the process of turning the emails over to the Senate Finance Committee, which is investigating whether the IRS wrongly targeted conservative and other groups seeking tax-exempt status, committee spokesman Aaron Fobes said.

“These emails will be carefully examined as part of the committee’s bipartisan IRS investigation,” he said.

After the IRS said last year that it was unable to produce all Lerner’s email, the Senate Finance Committee asked the Treasury inspector general to investigate what records were lost, if they were deliberately destroyed and if the missing information could be recovered.

The investigation is ongoing and the Treasury deputy inspector general has said officials are examining the possibility of criminal activity.

Because the inspector general is still turning over the emails to the committee, congressional staffers CNN spoke to were not familiar with their contents.

However, one staffer familiar with the investigation said the emails were from 2004 through 2013, with the bulk coming from 2012. About 650 are from 2010 and 2011, when the alleged IRS targeting began.

Tea Party Patriots president Jenny Beth Martin said the news was another development in a “long line of deplorable actions from the Internal Revenue Service against groups who were merely trying to hold their government accountable.”

“It will be very enlightening to see the content of the emails as (the inspector general) continues the investigation,” she said in a statement.