MADISON, Wis. -- An independent film is bringing to light a well-kept secret: Soviet dictator Josef Stalin's only daughter has been living incognito in Wisconsin.

It is unclear whether the 84-year-old, who fiercely guards her privacy still lives here today, but Lana Peters has lived at several addresses in southern Wisconsin in the last 20 years.

In the summer of 2007, a determined filmmaker tracked her down to an apartment at a retirement home in an undisclosed Wisconsin town for a rare interview that could be the last she ever grants.

A documentary based on the interview, "Svetlana About Svetlana," tells her complex life story, which is probably most noted for her defection to the U.S. in 1967.

On April 18, the film will be shown at the Wisconsin Film Festival in Madison.