Story highlights The officials said the FBI and CIA are coordinating reviews of the matter

The documents published so far are largely genuine, officials said

(CNN) A federal criminal investigation is being opened into WikiLeaks' publication of documents detailing alleged CIA hacking operations, several US officials told CNN Wednesday.

The officials said the FBI and CIA are coordinating reviews of the matter.

The investigation is looking into how the documents came into WikiLeaks' possession and whether they might have been leaked by an employee or contractor. The CIA is also trying to determine if there are other unpublished documents WikiLeaks may have.

CIA spokesman Ryan Tripani said the agency had "no comment on the authenticity of purported intelligence documents released by WikiLeaks or on the status of any investigation into the source of the documents."

But officials told CNN that the documents published so far are largely genuine, though they are not yet certain if all of them are and whether some of the documents may have been altered.

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