US intelligence officials are today considering whether to ask the US Department of Justice to open a criminal investigation into the suspected leak of a classified counter-terrorism document to a news website.
The intelligence officials were preparing a criminal referral over the publication on The Intercept of a document that provides a statistical breakdown of the types of people whose names and personal information appear on two government data networks listing people with supposed connections to militants, a US official said.
The Intercept - an investigative website co-founded by Grenn Greenwald, the reporter who worked with Edward Snowden on the majority of his leaked documents - published the new leak this week, but the document itself was dated August 2013, after Snowden left the US for Russia.
Snowden resigned from the NSA in May last year and is not known to have had access to any secret materials since then, leading US officials to suspect the drop may have come from a second leaker. One official said the government does not yet know for sure.
The document detailed information on the Terrorist Identities Datamart Environment database (TIDE) and the Terrorist Screening Database.
It said 680,000 names were "watchlisted" in the Terrorist Screening Database, an unclassified data network which is used to draw up more selective government watchlists.
It revealed 280,000 of the 680,000 people are described by the government as having "no recognised terrorist group affiliation." Around the same number of people on the list have suspected connections to several specific militant groups, including al Qaeda, Hamas and Hezbollah.
According to the document, the more selective lists include a "no fly" list totaling 47,000 people who are supposed to be banned from air travel, and a further "selectee list" of 16,000 people who are supposed to get extra screening by security personnel before being allowed to board aircraft.
The screening database is in turn extracted from TIDE, a larger, ultra-classified database which contains 320,000 more names than the unclassified one, as well as raw intelligence information excluded from the screening system.
Because the graphic carries a "secret" classification, an official said, the agency which generated it, The National Counterterrorism Centre, is obliged to consider submitting a referral to the Department of Justice, which then can decide if a criminal investigation should be opened into the leak.
Last month, The Intercept, which is financed by eBay founder Pierre Omidyar, also published a lengthy document setting out the criteria and procedures by which names are placed into terrorist watchlist databases. That document was labelled "unclassified/for official use only/sensitive security information."