Nuclear weapon plot deemed not credible

WASHINGTON (CNN) -- The Bush administration received information last October outlining a plot to smuggle a stolen Russian nuclear weapon into the United States, most likely New York City, two administration officials said Sunday.

The intelligence was viewed as suspect from the outset and later was deemed "not to be credible," as one official said, when a polygraph test determined the informant was "bogus."

Nevertheless, it was the source of an alert to government agencies charged with trying to prevent such a scenario, because there are "some things you can't afford to be wrong about," one official said.