(CNN) — The FBI is zeroing in on a US government office where it believes the leaked US intelligence documents on Israel’s preparations for a possible attack on Iran were printed, a US official and another source familiar with the matter told CNN. FBI investigators working with the Naval Criminal Investigative Service in recent days have narrowed the focus of the investigation to concentrate on locations where the documents could have been printed before they were leaked last Friday. In the wake of classified document leaks in recent years, the federal government has increased its tracking of when employees access and print classified documents.
Both Israel-related documents that were published on social media last week were widely accessible intelligence products, according to two sources familiar with US intelligence. But at least one appears to be scanned from an officially printed briefing book. Investigators have worked to pinpoint where the documents were printed and who had access to them.
The pool of people who printed these pages would be relatively small; sources have said — a key jumping-off point for investigators. US officials have said it wasn’t what the documents described that is worrying so much as the fact that they leaked at all; the breach has simmered in the background of national security circles in Washington throughout the week. The top Democrat and Republican on the Senate intelligence committee on Thursday urged FBI Director Christopher Wray .