Government watchdog groups have new questions about the Obama administration's commitment to executive-branch oversight after a Senate report showed that an acting inspector general played politics with his investigations and altered his reports to benefit senior officials.

A subcommittee of the Senate Homeland Security and Governmental Affairs Committee released a report Thursday detailing a series of ethical allegations against Charles Edwards, a former acting inspector general at the Department of Homeland Security who resigned his post in December and was transferred to different position with the agency.

DHS Secretary Jeh Johnson put Edwards on administrative leave last week after the report, which determined that he had “jeopardized the independence” of his office, went public.

A Senate probe found that Edwards, who served as acting inspector general from 2011 until December, had directed his staff to alter and delay investigations and reports to please top political appointees within the department who were in a position to influence President Obama to permanently elevate him to the top post.

The allegations leveled against Edwards in the report are giving watchdog groups new evidence for their concern about Obama's failure to fill inspector-general vacancies. There are currently nine inspector general vacancies throughout the executive branch, including at the Interior Department, the Agency for International Development and the Financial Deposit Insurance Corporation.

Interior's top inspector general position has been vacant since early 2009, when Obama first took office, according to the Project for Government Oversight, which tracks current vacancies.

“The long-term vacancies are inexcusable,” said Melanie Sloan, executive director of Citizens for Responsibility and Ethics in Washington, in reacting to the Senate report on Edwards. “It appears the Obama administration may not have appointed inspector generals because the administration is only interested in having watchdogs they can control.”

Because Obama has failed to nominate inspector generals and make their Senate confirmation a priority, interim inspectors generals have served for years in roles that should be reserved for full-fledged watchdogs, said POGO spokesman Joe Newman.

The Edwards case "raises serious questions we have had in the past about the roles of IGs who are appointed on an interim and temporary basis," he said. "The problem with temporary or acting IGs is that they don't have the same independence a permanent position would have or the same job security."

POGO believes the process needs to be changed to disqualify temporary IGs from being eligible to move into the permanent top watchdog role. The group issued a report earlier this year citing problems with acting inspector generals who may have jeopardized their independence.

Nathan Mehrens, president of Americans for Limited Government, a conservative group that scrutinizes the Obama administration and advocates for smaller government, said Edwards' story confirms the watchdog community's “worst fears that the president's failure to fill IG position damages the integrity of this important watchdog function.”

“The fact that Obama administration officials dared to try to pressure an acting IG to skew his reports shows a contempt for the watchdog process that is unparalleled,” he said.

Mehrens called on Congress to immediately eliminate Edwards' salary and pension and hold hearings to try to find out who in the Obama administration pressured him to violate the public trust.

“Whoever is involved in the manipulation of three separate IG reports should be immediately called to testify to learn if they were directed to do so by other political appointees,” he continued.

The offices of Sens. Claire McCaskill, D-Mo., and Ron Johnson, R-Wis., the senators who run the Homeland Security and Government Affairs subcommittee that investigated Edwards, did not immediately provide a comment.

The senators began looking into Edwards during a review of allegations that the DHS inspector general's office was involved in a cover-up of the 2012 scandal in which Secret Service agents were caught with prostitutes during a presidential visit to Colombia.

The 27-page Senate report on Edwards chronicles a long list of alleged personal vendettas and political games within the office. It quotes one unnamed official saying Edwards cultivated a “toxic, totally dysfunctional and oppressive” work environment based on personal vendettas and paranoia. Another official described the workplace atmosphere as one of “complete terror.”

Edwards resigned his watchdog post in December, three days before he was scheduled to testify on Capitol Hill. The Senate Homeland Security and Government Affairs subcommittee looking into the matter canceled the hearing when DHS transferred Edwards to the agency's office of science and technology.

The transfer of a top watchdog to another, lower-profile position in the administration is rare if not unprecedented, according to several Capitol Hill sources.

According to the report, Edwards put three of his staff on administrative leave after they balked when he directed them to delete parts of the office's investigation into Secret Service misconduct in Cartagena, Colombia — evidence that would have cast the Secret Service in a more negative light, as well as implicate a White House staff member.

A senior aide also said that Edwards ordered alterations to a March 2012 report looking into complaints that senior DHS officials intentionally misled Congress and the public about an Immigration and Customs Enforcement program aimed at identifying illegal immigrants called Secure Communities.