One possibility is that you saw a dubbed version of one of the French Fantômas films from the 1960s, starring Jean Marais. See The Fantômas Films for more information.
Without a doubt one of these is what I saw, because that is the timeframe during which I would have seen it. Also I know that I saw it on television, and am sure it was dubbed. Also, are the books available in English?
Unfortunately, none of the Fantômas books is currently in print in English. However, William Morrow reprinted (and "modernized") the first two novels in the series, Fantomas and The Silent Executioner (published as The Exploits of Juve in 1917 by Brentano's) about ten years ago, and they were also issued as pocket books by Ballantine shortly after. You can still often find them priced cheap in used book shops; look under "Allain" in their mystery sections. We'll be adding more novel synopses to the site over the next few months; eventually, of course, we hope to have synopses of all 32 novels. That won't be for a while, though.
I would be willing to bet that the books are in the public domain and actually could be published on the website, as many public domain texts of similar vintage are.
Almost certainly the original translations (published more than 75 years ago) are public domain. Thanks for the suggestion about posting the novels themselves on the site. Robin and I have already talked about it, but that project will have to be put off until we have sufficient free time to scan them (a huge job). But we probably will start posting the novels at some point in the future.