Two recently published books assert that famed French architect Le Corbusier was a fascist and Nazi sympathizer with links to France’s World War II Vichy regime. Both books—Xavier de Jarcy’s Le Corbusier, un fascisme francais (Albin Michel, 2015), and Francois Chaslin Un Corbusier (Seuil, 2015)—claim the architect was active in several fascist groups in France beginning in the 1920s, but did a good job of keeping his involvement under wraps.

“I discovered he was simply an out-and-out fascist,” de Jarcy told the AFP. In his book, he writes that Le Corbusier was close friends with Pierre Winter, a doctor who headed France’s Revolutionary Fascist Party, and worked with him to found the urban planning periodicals Plans and Prelude. de Jarcy claims that in the journal, Le Corbusier wrote in support of anti-Semitism.

Chaslin’s research uncovered anti-Semitic sketches attributed to Le Corbusier.

These shocking revelations come just as France is commemorating the 50th anniversary of the architect’s death (see A New Corbusier-Inspired Exhibition Opens to Coincide with the 50th Anniversary of His Death). On April 29, the Centre Georges Pompidou will open”Mesures de l’homme,” a retrospective on Le Corbusier.

The Le Corbusier Foundation, which is dedicated to preserving the architect’s legacy and work, vehemently denies these claims. Spokesperson Jean-Louis Cohen told the AFP that he was “shocked by this controversy.”

Meanwhile, organizers of the upcoming exhibition at the Pompidou have defended their omission of the fascism revelations by saying the show “doesn’t address the entire work” of Le Corbusier. The museum also noted that his time in Vichy, where the Nazis ran a puppet French government, was handled in a previous exhibition in 1987.

Chaslin and de Jarcy aren’t the first to come to these conclusions regarding Le Corbusier. Marc Perelman, an architect and scholar who has investigated the architect’s history and ideas for over three decades acquiesces that his findings have long pointed to fascist involvement and anti-Semitic beliefs.

“His ideas—his urban planning and his architecture—are viewed separately,” Perelman noted, “whereas they are one and the same thing.”