The Justice Department refused to act after being presented with evidence that a government official had "willfully" accessed private tax documents, it was reported Tuesday.
The evidence against the person was laid out in a letter from J. Russell George, the Internal Revenue Service inspector general.
He told top Republican Sen. Chuck Grassley he did not know why Justice had not acted, The Washington Times reports
"We presented evidence of a willful unauthorized access to the Department of Justice, but the case was declined for prosecution," George wrote in a letter to Grassley.
George said there was evidence of three other cases of government officials accessing tax documents since 2006, but that all three appeared to have been inadvertent. His department suggested that one of those cases not be prosecuted, and the Justice Department agreed, he said.
Now Grassley, the ranking member of the Senate Judiciary Committee, is looking for answers.
"The public needs to know whether the decision not to prosecute these violations was politically motivated and whether the individuals responsible were held accountable in any other way," he told the Times.
Grassley has asked Attorney General Eric Holder to explain before July 26 why his department chose not to prosecute the case.
"The Justice Department should answer completely and not hide behind taxpayer- confidentiality laws to avoid accountability for its decision not to prosecute a violation of taxpayer-confidentiality laws," he said.
In his July 12 letter to Holder, the Iowa Republican wrote, "Although this may not be indicative of widespread targeting, any instance is cause for concern, the Times reported.
"Decisions such as these directly impact the political process and should be subject to the scrutiny of the American public," he added.
George told Grassley he is investigating two cases where the IRS may have improperly targeted political candidates for audit. He would not reveal the identity or the political party of the people involved in any of the cases.
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