Using both open and clandestine sources, C.I.A. analysts determined the street address of the arms agency.

There is also speculation the group receives support from clandestine sources.

Not all clandestine human sources change their loyalties to the country to which they were born, or owed their first allegiance.

"We're getting important information from non-traditional clandestine sources who have better access to some of this information than the traditional espionage activity would have."

He learned through "a clandestine source in army intelligence," that he "would not be shipped overseas for political reasons."

Now, through some clandestine source, the news reached the ears of the six maids-in-waiting, to their delight.

She recognized it immediately as a reply from one of the clandestine sources Travis hadn't believed she sometimes worked with.

Early in the collection process, the specific identity of the source is removed from reports, to protect clandestine sources from being discovered.

I suspect they have clandestine sources of information from here.

This lists is restricted to organizations that operate clandestine human sources in foreign countries and non-national groups.