Jeanne Guillemin, an eminent medical anthropologist and scientific sleuth who helped expose a secret biological warfare lab in the Soviet Union as the source of a lethal anthrax outbreak, died on Nov. 15 at her home in Cambridge, Mass. She was 76.

Her husband, Matthew Meselson, said the cause was cancer.

Dr. Guillemin (pronounced GILL-men) was a prominent advocate for curbing the use of biological and chemical weapons. In the 1980s, she and her husband, a world-renowned molecular biologist at Harvard, undertook a series of investigations into biological warfare and how government programs were misusing biomedical science.

One of their most important investigations took place in 1992 in Russia, shortly after the fall of the Soviet Union. Along with a small team of American and Russian scientists, they examined 66 of perhaps 100 anthrax deaths that occurred in 1979 in the Ural city of Sverdlovsk, now Yekaterinburg.

The Soviet government claimed that the deaths were caused by the consumption of anthrax-tainted meat. American intelligence officials were skeptical, suspecting that the anthrax was a result of Soviet experiments with biological weapons in violation of a 1972 international treaty.