Vigilante who posted video of armed civilians tying up refugees arrested after claims that the Bulgarian government was turning blind eye to assaults

Bulgaria has announced investigations into several “migrant hunters” after being accused of turning a blind eye to vigilantes targeting refugees travelling to Europe from Turkey.

The interior ministry said on Tuesday that Dinko Valev, a semi-professional wrestler who boasted earlier this year of detaining migrants, had been summoned for questioning. In separate developments on the same day, the ministry said it had detained a vigilante responsible for a video released this week that showed armed civilians tying up refugees, and begun searching for others.

It follows an international outcry over the footage, which shows the individuals tying the people’s hands behind their backs, forcing them to lie facedown and shouting: “No Bulgaria! Go back to Turkey!” The video amplified claims that the Bulgarian government has not been doing enough to clamp down on vigilante activity along its border.

Facebook Twitter Pinterest Dinko Valev, a wrestler who boasted of having detained migrants earlier this year, was summoned for questioning Photograph: Vassil Donev/EPA

In an interview with the Guardian, the deputy interior minister, Philip Gounev, said the government was deeply opposed to citizens taking the law into their own hands. Announcing the investigations as evidence of this stance, he said: “Arresting people is only in the power of law enforcement and the police. Any attempts by citizens to arrest other citizens is illegal. Any kind of illegal detention of citizens by other citizens is treated as such.”

More than 30,000 people were recorded attempting to pass through the country from Turkey last year, despite a fence being erected along part of the border, and more may have passed through undetected. In response, groups of Bulgarian civilians have started to patrol the border, where they detain and rob those who are found.

Valev, 29, was described as a “superhero” in a state television report for his vigilante work. He later told the BBC: “These [migrants] are disgusting and bad people and they should stay where they are.”

That Valev was not summoned until Tuesday has been interpreted as a sign that the government was not initially serious about preventing vigilante arrests. This feeling was heightened when the prime minister, Boyko Borissov, made comments that were interpreted as being supportive of vigilantes. “Any help for the police, for the border police and for the state is welcome,” he said. “Anyone who helps deserves thanks.”

The Bulgarian border police chief, Antonio Angelov, was also perceived by some to have spoken out in favour of vigilantes after he said of Bulgarians who had reported migrants to authorities: “I want to encourage them, because they have reacted very appropriately.”

Gounev told the Guardian that his colleagues had been grossly misinterpreted. Borissov and Angelov were not talking about vigilantes, he said, but very specifically about good-natured people who had fed a group of lost migrants and helped them make their way to police.

“We consider this a noble act, and there is nothing indicated that they did anything illegal or detained migrants by force,” Gounev said.

Rights activists believe the government has fanned the flames of the situation. Margarita Ilieva, from the Bulgarian Helsinki Committee, said the prime minister should be arrested “for openly inciting the commission of crimes, and inciting violence and discrimination based on nationality, ethnicity or race”.

Ilieva claimed Borissov had knowingly praised vigilantes acting outside the law. “Borissov repeated many times that he thanked the ‘boys’ and that they only deserved thanks for the ‘help’ they were offering, and that the border police would cooperate with them,” she said. “This is a despicable insult to the very idea of a republic based on laws, due process and institutions.

“For the past three years, domestic officials at the highest levels … have engaged in deliberate, sustained, targeted propaganda [out] of fear of the refugees, with words such as ‘danger’, ‘threat’, ‘risk’, ‘wave’, ‘wall off’ being central to their discourse. As a result, now 60% of Bulgarians consider the refugees a threat to national security.”

• The subheading on this article was amended on 18 April 2016. An earlier version said Dinko Valev had been arrested; he was summoned for questioning but not arrested.