Grassley has sent a letter to the Justice Department asking why it declined to prosecute in the case of willful unauthorized access.

“Any agency with access to tax records is required to act with neutrality and professionalism, not political bias,” Grassley said in a statement. “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.”

“With the IRS on the hot seat over targeting certain political groups, it’s particularly troubling to learn about ‘willful unauthorized access’ of tax records involving individuals who were candidates for office or political donors,” Grassley said. “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.”

When asked for comment on Grassley’s letter, a Justice Department spokesman told the Washington Free Beacon, “We have received the letter and are reviewing it.”