The longtime inspector general for the National Archives and Records Administration has been placed on administrative leave with pay following allegations of professional misconduct made by a federal agent on his staff, officials said.

Paul Brachfeld, 54, was placed on leave Sept. 14 by Archivist of the United States David S. Ferriero, according to government and congressional sources with detailed knowledge of two pending reviews of the inspector general’s conduct. The agent has filed a complaint with the Council of the Inspectors General on Integrity and Efficiency alleging inappropriate conduct, the sources said. Greg Tremaglio was himself placed by Brachfeld on administrative leave with pay in August after a dispute with Brachfeld, the sources said.

In addition to the council, which reviews misconduct claims against inspectors general, the Office of Special Counsel is reviewing Brachfeld’s conduct, the sources said. The office, which investigates complaints of government wrongdoing and retaliation against whistleblowers, does not confirm or deny investigations.

William Carter, a spokesman for the council, declined to comment.

Tremaglio’s complaint, read to The Washington Post by a congressional source, included allegations that the inspector general altered audits, provided sensitive law enforcement information to reporters for CBS News’s “60 Minutes” before law enforcement officials approved its release, made derisive comments about transgender people, and used vulgar language with some female staff members.

Brachfeld denies the allegations and said that further investigation will show that he is innocent of any misconduct.

“I was informed that the archivist told a bipartisan gathering of congressional staff that upon my being exonerated, I will be reinstated as the NARA inspector general,” Brachfeld said by e-mail. “I look forward to the archivist honoring this commitment. Upon my return, I will resume a career marked by 33 years of honor, integrity and dedication to the American public.”

Complicating the case, the council meets just four times a year and has not opened a formal investigation, congressional and government sources said. Brachfeld may not be interviewed for months, which has led Sen. Charles E. Grassley (R-Iowa) to express concern that the inspector general may have been denied due process.

Tremaglio, hired from the Justice Department inspector general’s office in 2011, did not return messages left at his Maryland home.

Brachfeld has had a long career in the federal government that includes high-level auditing positions with the Treasury Department, the Federal Election Commission, the U.S. Customs Service and the Federal Communications Commission. Since his arrival as the Archives inspector general in 1999, he has built a reputation as a hard-charging, creative watchdog over the agency charged with preserving historical records.

He also has had a good working relationship with Ferriero, both men have said. Ferriero came to the Archives from the New York Public Libraries system in 2009.

Brachfeld has received plaudits for creating a team devoted to recovering stolen historical documents. Its biggest case to date is that of collector Barry Landau, a 63-year-old collector who was sentenced in June to seven years in federal prison for conspiracy and theft of thousands of historical documents from East Coast museums and historical societies. The documents were worth as much as $2.5 million.

Tremaglio was the federal agent who handled the case for the Archives. According to those familiar with details of the investigations, he and Brachfeld disagreed how much information on the case should be turned over to “60 Minutes.”

Brachfeld said he learned in late August that the inspectors general council had received a complaint. He was asked to respond by Sept. 11. Three days later, Ferriero placed him on administrative leave.

Ferriero did not respond to numerous e-mails seeking comment. An Archives spokeswoman declined to comment, saying agency personnel matters are not public.

Soon after he was placed on leave, Brachfeld met with Grassley’s staff and that of other Republican committees with oversight over the Archives. Grassley spokeswoman Jill Gerber said the senator is concerned that the independence of government watchdogs is at risk when an agency head removes an inspector general, since the two officials are in a naturally adversarial role.

“It’s worrisome to him when agency management removes an inspector general, even temporarily, without a clear explanation and good cause,” Gerber said in a statement. “Sen. Grassley is investigating this situation and working to gather all the facts. The Archivist’s decision to remove the inspector general is not an indication that the complaints against the inspector general are credible or have any merit. No independent review has yet been conducted.”