MADISON, Wis. — Newly declassified documents show the FBI kept close tabs on Soviet dictator Josef Stalin’s only daughter after her high-profile defection to the United States in 1967, gathering details from informants about how her arrival was affecting international relations.

The documents were released Monday to the Associated Press under the Freedom of Information Act after Lana Peters’s death last year at age 85 in a Wisconsin nursing home. Her defection to the West during the Cold War embarrassed the ruling communists and made her a best-selling author. And her move was a public relations coup for the United States.