The Obama administration is refusing to release more than 500 documents related to the Internal Revenue Service's targeting of conservative groups as investigations continue into the scandal, according to The Hill The newspaper sought access to the documents in a Freedom of Information Act request, asking for emails and other correspondence between the IRS and the Treasury Inspector General for Tax Administration (TIGTA) dating back to 2013.The request specifically asked for emails from former IRS official Lois Lerner and other high-level Treasury officials."TIGTA opted not to release any of the 512 documents covered by the request, citing various exemptions in the law. The Hill recently appealed the FOIA decision, but TIGTA denied the appeal," The Hill said, adding that TIGTA refused to comment for the article."It's par for the course. We've had a difficult time getting information from the IRS and the Department of Justice," Ohio Rep. Jim Jordan, a senior member of the House Oversight and Government Reform Committee, which has held numerous hearings on the IRS scandal, told The Hill.Republicans in both the House and the Senate are intensifying their investigations into the IRS and have criticized the agency and TIGTA for failing to inform Congress about the targeting in advance of the 2012 presidential election, and since stonewalling requests for transparency.According to "weekly activity reports" TIGTA sends to the Treasury secretary obtained through a FOIA request, IRS and Treasury officials had been regularly receiving briefings about the targeting, one as early as May 30, 2012.Jordan said neither the IRS nor TIGTA informed Congress at the time.TIGTA has come under fire in the past from outside groups for refusing to be forthcoming with other FOIA requests. Cause of Action, a nonprofit group, sued TIGTA after announcing in December that the agency refused to turn over more than 2,000 documents.Judicial Watch, a watchdog group, has also sued the Obama administration, saying in December that the Department of Justice has withheld 832 documents related to meetings between the IRS and the department's Public Integrity Section and Election Crimes Division.The Hill noted that Attorney General Eric Holder said last week that the department will soon release a report about the agency's targeting that will include "some final recommendations."Meanwhile, Senate Finance Committee Chairman Orrin Hatch said last week the IRS recently turned over 86,000 pages of new documents to his panel."These documents … were given to us without notice or explanation roughly twenty months after we made our initial document request [on the targeting]," he said, according to The Hill.