Footage of the summary killing of Yevgeny Nuzhin was released over the weekend by the Wagner-affiliated Telegram channel Gray Zone. In the video, Nuzhin was seen lying with his head against a brick wall as an unidentified man in combat clothing hit him with a sledgehammer. Nuzhin, 55, was serving a 24-year sentence for a murder he committed in 1999 when he was released in July and recruited into Wagner, a notorious military group run by Yevgeny Prigozhin, a powerful Russian businessman and close ally of Vladimir. Putin. After his arrest by Ukrainian forces in September, Nuzhin gave a series of interviews in the country, in which he said he had joined the Wagner group to get out of prison and that he quickly worked out a plan to surrender to Ukraine. In the interviews, he also criticized the Russian leadership and expressed his desire to join the Ukrainian forces and fight against Moscow. Ilya Nuzhin, Yevgeny’s son, confirmed to the Guardian on Monday that the man in the video was his father, but declined to comment further, citing “security concerns”. In an interview with Russian human rights group Gulagu.net late Sunday, Ilya Nuzhin said his family learned of their father’s death via Telegram, which left them “horrified.” “Our whole family was in tears watching the video … they killed him like an animal,” Nuzhin said. It was not immediately clear who was behind the video or how Nuzhin would have ended up back in Russia. Unconfirmed reports said Nuzin was part of a recent prisoner swap between Russia and Ukraine, news that has led to concerns among human rights groups. “There are a lot of questions, and I hope we get to the bottom of it,” Vladimir Osechkin, head of Gulagu.net, a rights group focused on alleged abuses in Russia’s prison system, told the Guardian. “Ukraine had a responsibility to Nuzhin and he should not be traded, given the risks he faced in Russia.” Osechkin said all signs pointed to Wagner’s involvement in the murder and said he plans to send a request to Russian authorities to open a criminal case. “Wagner could not have carried out this medieval execution without the approval of the Russian security services,” Osechkin said. Prigozhin, who is under Western sanctions for his role in Wagner, on Sunday expressed his approval of the killing, calling Nuzin a “traitor”. “Nuzin betrayed his people, betrayed his comrades, consciously betrayed,” he said. In September, Prigozhin, known as “Putin’s chef” because his catering business hosted dinners attended by the Russian president, admitted setting up Wagner, a link he has repeatedly denied. Wagner has repeatedly been accused of war crimes and human rights abuses, including torturing and killing prisoners in Syria, where he fought alongside the Russian military and Bashar al-Assad’s government. The Kremlin on Monday sought to distance itself from the video, which has been widely discussed on Russian social media, with spokesman Dmitry Peskov saying “it was none of our business”. The Guardian previously reported that Prigozhin was personally recruiting soldiers from Russia’s sprawling prison system in a bid to compensate for acute battlefield shortages. According to a Russian human rights group, Wagner has so far recruited more than 20,000 prisoners to fight in Ukraine. There were also widespread reports that Wagner was recruiting foreign convicts in prisons across Russia, including citizens from the five central Asian states. On Monday, Zambia’s foreign minister said a 23-year-old Zambian national who was serving a prison sentence in a prison on the outskirts of Moscow ended up fighting in Ukraine, where he was killed.