The National Security Agency (NSA) doesn’t know how much information leaker Edward Snowden was able to obtain because of an underdeveloped capacity to audit its own data, according to a NBC News report released late Tuesday. 

The report says investigators trying to determine what Snowden was able to obtain, and how many more stories might still be on the way about the secretive agency, are “overwhelmed” in trying to assess all of Snowden’s potential security breaches.

According to the NBC report:

“The NSA had poor data compartmentalization, said the sources, allowing Snowden, who was a system administrator, to roam freely across wide areas. By using a 'thin client' computer he remotely accessed the NSA data from his base in Hawaii.

One U.S. intelligence official said government officials 'are overwhelmed' trying to account for what Snowden took. Another said that the NSA has a poor audit capability, which is frustrating efforts to complete a damage assessment.”

Officials who spoke to NBC under the condition of anonymity said Snowden may be sitting on details about NSA-style programs being conducted by U.S. allies in the United Kingdom, Canada, Australia and New Zealand.

Snowden downloaded the NSA documents while he was a contractor for Dell Inc. in April, 2012, and up until this year as a contractor at Booz Allen Hamilton. The documents he obtained turned into The Guardian’s explosive reports on government surveillance, and have since been explored deeper by other media outlets.

The Russian government has granted Snowden temporary asylum. The U.S. government wants Snowden sent back to face trial on espionage charges.