Now we can understand why Jacques Ducrez shifted his guise from Jacquemez to Le Bouurea de Béthune in about 1965. He was in fact the second Bourreau, the original having retired through injury that year.
The original was Freddy Robert (real name Robert Moreau). It was he in the fifties and early sixties had the legendary mask v mask matches with L'Ange Blanc. The absolute heyday of French wrestling.
Here are some translations of texts I have found:
"Before, people used to say to me, 'My father saw you at Wagram in 1960.' Now, it's more like, 'My grandfather told me about you.'" In Laà-Mondrans, Robert Moreau, aka Freddy Robert, aka "the Executioner of Béthune," cultivates the discreet nostalgia of a man caught up in old age. It's here, near Orthez, that the once-legendary wrestling legend retired. Not the body-built, pumped-up, US-glitzy wrestling that's been a hit with teenagers for the past few years. No, this French-style wrestling, reminiscent of Chéri Bibi, and reminiscent of Audiard's atmosphere, the gentle France of the 1950s and 1960s. Well, not so gentle when you learn of the 17 broken bones Freddy Robert suffered during his career. At the time, he was, along with the White Angel, one of the legendary figures among French wrestlers, capable of drawing crowds. "I often saw kids in the streets of Paris playing The Executioner of Béthune," says Robert Moreau, who doesn't dwell on his glory years. Which lasted only six years, in all, at the turn of the 1950s into the 1960s. At the time, Freddy Robert (his wrestling name) was busy in Germany, where he had a television contract, when one of the main organizers..."

Freddy worked subsequently as a bodyguard for Jean Marie Le Pen. Here's a snippet from there:
"Thierry Légier was 27 when he began his service with Le Pen in August 1992, replacing Robert Moreau, alias "Freddy, the Executioner of Béthune," a former wrestling star from the 1960s, who had made his mark on ORTF evenings, commentated by Claude Darget and Roger Couderc. A colossus who would crush your hand while greeting you, a broken face, and cauliflower ears that would make Légier look like a first communion student. "
And from Le Monde:
"Béthune, a sub-prefecture of Pas-de-Calais, is famous for its donkey and its executioner. The unpredictable equine legend refers to the medieval philosopher Jean Buridan, and the axe-wielding artist belongs to the anthology of Alexandre Dumas. Bearing the terrifying title of "Executioner of Béthune", Freddy Robert, whose real name was Robert Moreau, haunted the rings of France in the 1960s. Wrestling fans have kept the vague memory of a mountain of muscles (183 centimeters) harnessed, in red, from head to toe, who was supposed to play the role of the villain under the boos of the crowd. A quarter of a century later, the man has lost a lot of weight, but he trains regularly in his gym and runs 10 kilometers daily. "Freddy", who became Mr. Jean-Marie Le Pen's bodyguard......."

Looks like we have been quite wrong all these years, though we have correctly named the visiting wrestler, if not the initiator.
Until now.
A new confusion emerges as we try to unravel who was who in the photos we have. Above is certainly Freddy. Quite why the masked man also had a pseudonym remains unclear.
SaxonWolf has done the business and found Freddy in Britain in May 1958. Well done Saxo. There is a question mark. The website with that information did get results from Ray, which are not entirely accurate. The match was part of the RAH heavyweight tournament. The RAH archive site does not list Freddy as taking part that night. It's a toss up which is right. Was he a substitute or was he substituted?
I've also found comments that Freddy was one of the wrestlers working as L'Homme Masque.