In 2015, Mr Cintula founded the campaign group Against Violence and sought to get it officially registered in Slovakia. “Violence is often a reaction of people, as a form of expression of ordinary dissatisfaction with the state of affairs. Let’s be dissatisfied, but not violent,” a petition that he circulated said.

The suspected gunman’s son told local media he was in shock, saying his father owned the gun legally.

“I have absolutely no idea what father intended, what he planned, why it happened,” he said.

Asked whether his father hated Mr Fico, he said: “I’ll tell you this – he didn’t vote for him. That’s all I can say about it.”

Unverified video footage emerged on Wednesday of Mr Cintula saying he did not agree with Mr Fico’s “government policy”. In another social media post, he criticised the Fico government for not cracking down on gambling.

The suspect’s political leanings appear to have shifted over time. He was once pro-Russian, and railed against “eyeless gypsies” and migrants before shooting the populist prime minister, who is fiercely anti-migrant.