French police found weapons and a copy of Hitler's infamous book Mein Kampf when they searched the homes of two men arrested after French President Emmanuel Macron was slapped in the face on Tuesday, French media reported.
The slapper has been identified as Damien Tarel, a 28-year-old medieval history fan with links to the royalist far-Right, who teaches European martial arts, according to posts on his social media accounts.
Tarel was arrested on Tuesday alongside Arthur C, who filmed the scene, and both were placed in custody for "voluntary violence on a person holding public authority".
They were still held on Wednesday, an official source told Reuters.
As part of the ongoing investigation into the incident, police searched the homes of both men and found firearms and a copy of Mein Kampf at the home of Arthur C, whose surname has not been made public, French broadcasters including TF1 and BFM TV reported.
Neither of them had a previous criminal record and their motives were unknown, Valence's public prosecutor, Alex Perrin, said late on Tuesday.
But a scan of Tarel's social media showed him following many accounts and influencers associated with the far-Right and royalist groups.
In his small village of Saint-Vallier, he founded a European martial arts group to revive the practice which has 1500 practitioners in France and includes swordsmanship.
On social media, he can be seen posing with swords and dressed as a knight or taking part in weekly medieval figurine board games.
In a video that quickly went viral on social media, Macron could be seen walking towards a crowd of well-wishers during an official visit in the southeastern Drome department.
As Macron approached, Tarel grabbed his forearm and shouted out "Down with Macronia" ("A bas la Macronie") and "Montjoie Saint-Denis," a 12th-century battle-cry of the French royal armies now used by the far-Right.
In an interview with local newspaper Le Dauphiné Libéré just after the incident, Macron said: "We cannot let ultraviolent individuals take possession of the public debate. They don't deserve it."