Even before Ms. Le Pen’s remarks this week denying France’s culpability in a notorious wartime roundup of Jews, recent revelations in the French news media, including a well-documented new book, revived nagging concerns about the sympathies of the woman who would be France’s next president.

Two men in her innermost circle — Frédéric Chatillon and Axel Loustau — are well-known former members of a violent, far-right student union that fought pitched battles with leftists and took a turn toward Hitler nostalgia in the mid-1990s.

They have been associates of Ms. Le Pen since her days in law school in the 1980s and remain among her closest friends, according to numerous accounts.

French television recently broadcast video from the 1990s of Mr. Loustau visiting an aging prominent former SS member, Léon Degrelle, a decorated warrior for Hitler and the founder of the Belgian Rex party, a prewar fascist movement.

Other video showed Mr. Chatillon speaking warmly of his own visit with Mr. Degrelle, who was a patron saint of Europe’s far-right youths until his death in 1994.