A pair of U.S. senators has written to IRS Commissioner Douglas Shulman and the heads of a dozen other federal agencies asking why they have erected roadblocks to investigative efforts of their agencies’ watchdogs, their inspectors general.

Senate Finance Committee ranking member Charles Grassley, R-Iowa, and Homeland Security and Governmental Affairs Investigations Subcommittee ranking member Tom Coburn, R-Okla., sent 13 letters earlier this month to the heads of the various agencies asking for an explanation. Back in April, they had sent letters to 69 inspectors general asking about any agency interference they had experienced.

In the IRS letter, they noted that the Treasury Inspector General for Tax Administration had outlined a number of examples of being denied unrestricted and unfettered access to information from the IRS. TIGTA said that it had requested numerous funding, approval and management oversight documents that the IRS delayed providing. The IRS’s 2010 Business Systems Modernization Expenditure Plan was delayed three months, and its Integrated Financial System reports took two months to obtain.

It also took 116 days for the IRS to complete a scanning project for TIGTA on a sample group of 20 databases, and another 42 days for the scan results to be shared with the database administrators so they could coordinate a review. TIGTA believed it would not have taken as long if the IRS had placed the necessary emphasis on the project.

In addition, TIGTA bristled at a provision in the IRS’s GovTrip Document Management and Records Control Plan that said, “GovTrip shall provide a capability for IRS to limit access by TIGTA auditors to specific vouchers or authorizations.”

The senators complained that TIGTA has also experienced several instances where the documents requested were required to be reviewed and cleared by various levels of managers at the IRS before they could be released to the government watchdogs. In addition, when TIGTA contacts IRS employees directly, employees have informed the inspector general representatives that they have been instructed by their managers to not speak with TIGTA representatives without their managers or liaisons present.

“It is unacceptable that TIGTA is not allowed unfettered access to documents and employees,” wrote the senators. “Management pre-screening of documents is not consistent with the Inspector General Act.”

“Inspectors general can’t conduct effective oversight of tax dollars and programs when the very agencies subject to the oversight impose delays, red tape and roadblocks,” Grassley said. “To let this continue in the executive branch is letting the fox decide who gets in the henhouse.”

“Good government starts with good oversight,” said Coburn. “When officials block investigations, they do nothing more than protect the people and processes that waste billions of taxpayer dollars every year. Inspectors general are the unsung heroes of Washington. Every day they fight battles to save taxpayers money. Officials who would deny them the documents and information they need to prevent waste, fraud and abuse, are doing the American people a great disservice and cannot be called public servants.”