Figure in Nuclear Probe Said to Have Failed Polygraph Test

A Taiwan-born American scientist, who is suspected of turning over to China design information about a key U.S. nuclear missile warhead 10 years ago, failed a polygraph test last month, according to administration sources.

The scientist, who worked on classified weapon designs in the 1980s and 1990s at the Department of Energy’s Los Alamos National Laboratory in New Mexico, became a suspect in an FBI espionage investigation that began in 1996.

As reported earlier by the Wall Street Journal and the Washington Post, the FBI inquiry that led investigators to suspect the unnamed scientist was begun after U.S. intelligence in 1995 obtained a top-secret Chinese nuclear weapons document from the late 1980s. That document indicated that Chinese scientists had become aware of techniques employed by U.S. scientists to miniaturize the shape of nuclear materials to get an explosion 20 times more powerful than that of the Hiroshima bomb.

The New York Times reported Saturday that the scientist failed a polygraph exam during the investigation into how Chinese scientists learned of the miniaturization technique.

The design had been tested in the late 1970s and was built in the early 1980s into the W-88 warhead that is carried on Trident II submarine-launched intercontinental missiles. The small size and shape allow missile builders to pack more than one warhead on a long-range missile.

The scientist was not arrested, Reuters news service reported.

A White House official Saturday denied the New York Times report that the Clinton administration had sought to minimize the Chinese espionage because it was seeking to establish a strategic partnership with the Beijing government.

“We recognize as a fact of international life that countries spy on each other,” the official said, “but we have other strategic interests to pursue. We carry on with a lot of countries, including allies, that we feel are spying on us. . . . There are very few countries we could cooperate with if spying were a defining issue.”

The official would not say whether the 1988 Chinese document that triggered the probe was obtained by U.S. spies.