Dozens of United States inspectors general are protesting what they see as efforts by the Obama administration to impede or stall their investigations.

The group of inspectors general - independent watchdogs within federal agencies - sent a letter to Congress this week citing instances in which their counterparts at the Justice Department, Environmental Protection Agency, and the Peace Corps said they were blocked timely access to documents and other information in the process of investigations.

The letter also says that other inspectors general have experienced similar stonewalling, and that Congress may need to take action to demand government agencies cooperate with watchdogs.

"Refusing, restricting, or delaying an Inspector General's access to documents leads to incomplete, inaccurate, or significantly delayed findings or recommendations, which in turn may prevent the agency from promptly correcting serious problems and deprive Congress of timely information regarding the agency's performance," the group wrote.

The inspectors general said that the Peace Corps did not offer full access to records during an investigation into how reports of sexual assaults against volunteers were handled by the program. A Peace Corps spokeswoman said in a statement, according to AP, that the program respected the investigatory process and had recently signed an agreement with the office to provide more documents, but that it also must protect the privacy of volunteers who are sexually assaulted.

The letter criticized the Justice Department for initially withholding documents during three watchdog reviews, and that when the records were later provided, it was only "based on a finding that the three reviews were of assistance" to department officials and not out of a desire to cooperate with the inspector general.

Justice Department spokesman Brian Fallon said the documents in question included grand jury information, credit reports, and other material that the department was restricted by law to provide. He said that before the materials could be given to the watchdog, the department had to ascertain what exceptions to the law could apply.

Finally, the letter cited a records fight between the EPA inspector general and the Chemical Safety and Hazard Investigation Board, which investigates handling of industrial chemicals.

Addressing the complaint, the agency said it was concerned about offering requested personnel information based on attorney-client privilege, but that it eventually offered the materials and that Congress could ease such disputes in the future by clarifying that agencies won’t waive attorney-client privilege by cooperating with an inspector general’s request for certain information.

Sen. Chuck Grassley, the ranking Republican on the Senate Judiciary Committee, said he was alarmed by the inspectors general letter and that he would work to provide oversight or legislation to soothe access disputes.

"How are the watchdogs supposed to be able to do their jobs without agency cooperation? Inspectors general exist to improve agencies and get the most bang for every tax dollar," he said in a statement.

The Obama administration has been criticized before for censorship and a significant lack of transparency. In March, an AP investigation found that the administration “more often than ever censored government files or outright denied access to them.”

“The administration cited more legal exceptions it said justified withholding materials and refused a record number of times to turn over files quickly that might be especially newsworthy,” AP wrote. “Most agencies also took longer to answer records requests, the analysis found.”

Last month, 38 journalism groups criticized the Obama administration for severely limiting access to federal agencies and a general politically-motivated suppression of information despite the president’s pledge of historic transparency.

Internally, the administration’s close-lipped policy has, at times, bordered on the absurd. As RT reported in May, a pre-publication review from the Office of the Director of National Intelligence announced a prohibition for both current and former officials from publicly acknowledging disclosures of classified information, such as the NSA leaks provided by former government contractor Edward Snowden. Even if leaks are being discussed by the media, the review said, officials must still turn a blind eye to them or face penalties.