[7] The newspaper was bought by Cino Del Duca in 1957, causing Frémontier to join Paris-Jour, where he was appointed editor-in-chief of political news.
In 1969, Frémontier joined the Office de Radiodiffusion Télévision Française (ORTF) thanks to his friendship with leaders such as Jacques-Bernard Dupont, Claude Contamine, and Jacques Thibaud.
He produced the series Vivre aujourd'hui from 1970 to 1973, where he worked with journalists such as Daniel Karlin, Michel Pamart, Paul Seban, and Marcel Trillat.
Frémontier often called for open, democratic public television,[8] supporting the beliefs of the French Communist Party, of which he was a member.
He completed his doctoral thesis in 2000, supervised by Nancy L. Green, and titled Les Juifs communistes en France depuis 1945 : essai d’histoire orale.