Former IRS official Lois Lerner whose emails mysteriously disappeared amid a congressional investigation into the Tea Party targeting scandal had warned her colleagues to be careful about "what we say in emails" during an internal discussion last year, according to new emails released by House Oversight Republicans. The emails are the latest fodder released by Republicans in their case against Lerner, who has been accused of processing Tea Party and conservative groups' for tax exempt status in an unfair manner before the 2010 and 2012 elections.

During a House oversight committee hearing on Wednesday, Rep. Darrell Issa, R-Calif., brought up the email inquiry while stating his concerns about Lerner's missing emails to IRS Commissioner John Koskinen, Fox News reported. However, Koskinen, who was there to speak on improper government payments, said he was not there to defend Lerner, who has asserted her Fifth Amendment right not to testify before Congress twice and been held in contempt of Congress by the House since. "I'm not here to defend Lois Lerner. I've never met her. She doesn't work at the IRS anymore," he said, later adding: "No one should do anything to evade oversight."

The new internal IRS chat system revealed that after cautioning her staff to be careful about their emails on April 9, 2013, Lerner also asked whether the IRS's internal messaging system could be searched by Congress in an email to IT employee Maria Hooke, less than two weeks after the IRS inspector general that unearthed the tea party targeting practice shared a draft report with the agency.

"I was cautioning folks about email and how we have had several occasions where Congress has asked for emails and there has been an electronic search for responsive emails - so we need to be cautious about what we say in emails," she wrote to Maria Hooke, the director of business systems planning for the tax-exempt division. "Someone asked if OCS conversations were also searchable - I don't know. ... Do you know?"

Hooke responded that the messages "are not set to automatically save" but anyone could "copy and save the contents" to an email or file. She recommended that the agency treat these conversations "as if it could/is being saved [somewhere], as it is possible for either party of the conversation to retain the information and have it turn up as part of the electronic search." Lerner replied, "Perfect." 

Accusing Lerner of attempting to hide IRS information, Republicans latched onto the new correspondence and reprimanded the IRS for only now telling the panel that there is a whole other method in which agents could communicate, Politico reported. "For her to be worried right on the heels of this draft IG report that Congress may search her instant messages. ... That is very troubling," said Rep. Ron DeSantis (R-Fla.)

Republican lawmakers remain skeptical about IRS claims that Lerner lost her own email records after a hard-drive crash in 2011, Fox News reported. The IRS notified Congress of the lost emails last month, but claims they've already been able to recover tens of thousands of emails by going to other accounts. 

Ways and Means is one of three congressional committees investigating the way the IRS processed applications for tax-exempt status. The Justice Department is also investigating.