An audit of the Bureau of Alcohol, Tobacco, Firearms and Explosives released Tuesday reveals the agency’s messy record keeping leaves government officials blind to the whereabouts of some foreign nationals turned confidential informants.

The Department of Justice’s Office of Inspector General audit identified multiple issues with the ATF’s management of more than 1,800 confidential informants between 2012 and 2015 — including conflicting information about the legal statuses of foreign nationals sponsored for citizenship by ATF agents for the purpose of furthering an investigation.

“The use of sponsored CIs in this manner can be especially problematic due to the higher-than-normal risks associated with these CIs remaining in the United States without legal authorization, because they often have criminal histories or are involved with criminal organizations,” the OIG report says. “Because we found that information related to foreign national CIs was not completely or accurately tracked, we were unable to determine whether ATF fulfilled its obligation to coordinate with DHS on foreign nationals with expired sponsorship.”

As of March 2016, ATF officials maintained an electronic spreadsheet of 32 non-citizen informants, however, the audit indicated the document lacked complete data about each informant. Only four of the informants were registered with the National CI Registry as foreign nationals, against the guidelines of the Attorney General adopted by the ATF in 2012.

“Three CIs were recorded twice on the spreadsheet with two different sponsorships,” the audit says. “Also, the spreadsheet did not clearly or consistently indicate the legal status of foreign national CIs, nor did it always track the expiration of CI sponsorships. Further, it did not indicate whether ATF had taken action with DHS on those CIs with expired or terminated sponsorship.”

The audit flagged the file of a foreign national activated in 2007 as an informant. Guidelines require field offices to provide monthly status reports on foreign nationals, though several were missing from the file, the office found. When agents deactivated the informant in 2014, no one notified the Department of Homeland Security, either, the audit uncovered.

In another example, the agency failed to update the pending legal status of a deactivated informant.

“We believe that this illustrates the weaknesses in ATF’s administration of its responsibilities related to sponsored foreign national CIs,” the audit says. “Specifically, if the CI was deactivated, the sponsorship application should not have continued to be pending with DHS, or the spreadsheet should have been updated to reflect the current status of the CI.”

The findings corresponded with the agency’s overall “compartmentalized” record keeping system “that depends heavily on hard copy files.”

“As a result, ATF could not efficiently obtain accurate and complete information about its program as a whole and therefore could not manage the program efficiently or judge the overall value of informants,” said Michael Horowitz, the DOJ’s inspector general in a recorded statement Tuesday.

The agency, according to the audit, agreed its tracking system was “in need of improvement.”

“ATF has already modernized its CI record keeping system and has specific plans to add additional enhancements to the new, automated system in the immediate future,” the agency said, noting the implementation of its Confidential Informant Master Registry and Reporting System in October 2016. “ATF will continue using CIMRRS with features to provide additional layers of oversight for managers, improved tracking for other special categories of CIs, as well as improved historical data preservation.”