The Internal Revenue Service denied the existence of any documents related to its policy of targeting Tea Party organizations in response to a 2010 Freedom of Information Act request, even though such documents were later discovered by the IRS inspector general.

The 1851 Center for Constitutional Law, a conservative nonprofit group, filed a FOIA request in 2010 through investigative journalist Lynn K. Walsh seeking all IRS documents related to the agencies tax-exempt division specifically mentioning the Tea Party.

IRS headquarters responded in 2011 that it "found no documents specifically responsive to your request."

However, the May 14 inspector general report found that the "first Sensitive Case Report [identifying Tea Party groups] was prepared by the Technical Unit" in April of 2010.

The report's timeline chronicles the existence of numerous 2010 emails, memoranda, and policies related to the targeting of conservative organizations.

According to the IG timeline, an email was sent on July 27, 2010 "updating the description of applications involving potential political campaign intervention and providing a coordinator contact for the cases."

"The description was changed to read, ‘These cases involve various local organizations in the Tea Party movement [that] are applying for exemption under 501(c)(3) or 501(c)(4).’"

The IRS determinations unit developed a "be on the lookout" listing on Aug. 12, 2010, "in order to replace the existing practice of sending separate e-mails to all Determinations Unit employees as to cases to watch for, potentially abusive cases, cases requiring processing by the team of specialists, and emerging issues."

The language of the listing was identical to the July 27, 2010 email.

"Either IRS Headquarters was entirely incompetent in maintaining awareness of prominent policies and documents within the IRS, or it deliberately covered up the existence of anti-conservative IRS policies. Either is terrifying," Maurice Thompson, Executive Director of the 1851 Center, said in a statement. "Legal action is necessary to ensure that the IRS does not lie to taxpayers in this manner in the future."

The 1851 Center was one of many conservative organizations targeted by the IRS. When the 1851 Center applied for tax-exempt status in May 2010, the IRS demanded the organization "explain in detail your organization's involvement with the Tea Party."

As reported by the Washington Free Beacon, the IRS submitted inappropriate questions to numerous conservative groups, demanding information such as donor lists and reading materials.

The revelation, which confirmed nearly a year of suspicions among conservative groups and lawmakers, has been roundly denounced as a breach of core constitutional values.

"Obviously that behavior is intrusive and abusive, and most importantly it's not a standard question," said Ken Boehm, the cofounder of the National Legal and Policy Center. "You don't see things like that being applied across the board or even close. At it's base, its an equal protection thing."

The conservative Leadership Institute produced more than 23,000 pages of documents and spent more than $50,000 defending itself against what it says was a "harassing" IRS audit. The IRS requested information on the Leadership Institute’s interns, including their future employment.

Bloomberg reported that the IRS sought information from the Hawaii Tea Party on its relationship with the institute. Specifically, the IRS wanted to know if Dylan Nonaka, former executive of the Hawaii Republican Party, had trained the Hawaii Tea Party.

The IRS also demanded information about the group’s board members, officers, and employees, as well as their family members.

Tax information of other conservative groups, such as Crossroads GPS, the Texas Public Policy Foundation, and the National Organization for Marriage, were leaked and fell into the hands of political opponents.

Yahoo News reported Wednesday that Media Trackers, another conservative organization, waited more than a year trying to obtain tax-exempt status from the IRS. After reapplying under the name "Greenhouse Solutions," its application was approved in three weeks.

Media Tracker’s "determination specialist" at the IRS was Stephen Seok in the Cincinnati office. Seok also demanded donor lists from the Richmond Tea Party.

The IRS did not immediately return requests for comment.