Jeannie de Clarens, an amateur spy who passed a wealth of information to the British about the development of the V-1 and V-2 rockets during World War II and survived stays in three concentration camps for her activities, died on Aug. 23 in Montaigu, southeast of Nantes, France. She was 98.

The death was confirmed by her son, Pascal.

In 1943 Jeannie Rousseau, as she was then known, was an interpreter in Paris for an association of French businessmen, representing their interests and helping them negotiate contracts with the German occupiers. She was young and attractive. She spoke flawless German. She was a favorite with the German officers, who were completely unaware that the woman they knew as Madeleine Chauffour had been reporting to a French intelligence network, the Druids, organized by the Resistance.

Getting wind of a secret weapons project, she made it her mission to be on hand when the topic was discussed by the Germans, coaxing information through charm and guile.

“I teased them, taunted them, looked at them wide-eyed, insisted that they must be mad when they spoke of the astounding new weapon that flew over vast distances, much faster than any airplane,” she told The Washington Post in 1998. “I kept saying, ‘What you are telling me cannot be true!’ I must have said that 100 times.”