A former U.S. Park Police chief accused by a government watchdog agency of keeping his department-issued handgun for 10 years after he retired in 2001 has disputed the findings and said a report issued last week falsely labeled him a criminal.

Robert Langston, a 35-year veteran of the force, said he has paperwork to prove the gun was legally transferred from the Park Police to his next assignment, head of security at the U.S. Department of Housing and Urban Development. He said he returned the gun to the government when he retired from HUD in 2010.

A report issued last week by the inspector general for the Interior Department cited Langston as part of what it called the Park Police’s decade-long failure to keep track of thousands of its weapons. The investigation began with an anonymous tip that officers were taking their weapons home without anyone realizing it.

Investigators said that because records were so poorly kept, they were unable to prove the allegations, but they cited a few examples, among them Langston’s. They said his Heckler and Koch pistol was “unaccounted for on inventories following his retirement” and was located only after a federal agent noticed Langston using it at a firing range and seized it.

The retired chief said in an interview Monday that his successor gave him permission to take the gun with him to his new assignment because Park Police was phasing out that model. He said he kept the transfer record and has since faxed it to Chief Teresa Chambers. He provided a copy of the receipt to The Washington Post.

The Park Police report from the Office of the Inspector General.

“I’m not pleased that the IG did not give me the courtesy of reaching out to me,” said Langston, who lives in Potomac. “Nobody reached out to me.” The Post was unsuccessful reaching him Thursday, when the report was issued.

“When I left the Park Police, I didn’t walk away with a gun,” Langston said Monday. “Basically, I’ve been branded a thief. I’m not guilty as charged. My feeling is that this property audit was done by a bunch of bean counters. What they’ve said is based on hearsay evidence. They didn’t go and verify.”

David Little, who is in charge of the integrity division for the Interior Department’s inspector general, said there was no intention to question Langston’s integrity. He said the account of his gun being seized at a firing range was provided by the Park Police officer in charge of gun inventory. Little said no follow-up was done with Langston because the emphasis was on the missing records.

Little said the only document the agency had was the transfer from HUD back to the Park Police. Little, who supervised the investigation, said Park Police did not have the documents Langston has since provided. He noted that the missing document provided by Langston proves the underlying point of the report that paperwork on guns remains missing.

The chairman of the Fraternal Order of Police, which represents U.S. Park Police officers, also criticized the inspector general’s report, saying it unfairly holds current officers and supervisors responsible for a decade’s worth of problems.