A new investigation has cast doubt on the conviction of a prominent Ukrainian human rights defender and anti-fascist activist in Russian-occupied Luhansk, in the east of the country.

Maksym Butkevych was sentenced to 13 years in prison on 10 March, for attempted murder and violating the customs of war in Severodonetsk, a city occupied by Russia in summer last year. A court in the self-proclaimed “Luhansk People’s Republic” announced it had convicted the veteran activist of firing a grenade launcher at two civilians during the battle for the city on 4 June 2022.

But message logs between Butkevych and colleagues suggests he was not in Severodonetsk on the day in question.

Graty, a Ukrainian media outlet that focuses on the law and justice system, acquired the correspondence during its investigation into Butkevych’s conviction.

Alexander Butkevych, Maksym’s father, said: “There is not a word of truth in the so-called verdict.”

Butkevych was taken prisoner last summer while fighting in eastern Ukraine; his capture was announced on 24 June by Russian forces, who published a video of his interrogation online.

Russian state media then launched a campaign to discredit the activist, presenting him as a “Nazi” guilty of attacking civilians – in stark contrast to his background in pro-refugee and anti-fascist and anti-racist organising in Ukraine.

“It’s so Orwellian,” former student activist Yevheniia Polshchykova told openDemocracy at the time. “They literally take an anti-fascist, a human rights defender, and call him a Nazi.”

The last time Alexander Butkevych heard from his son was on 18 June last year, when he received a message that simply said: “Everything is fine.” The next day, his son’s unit went to the frontline.

The only communication of any kind since then has been a single phone call Butkevych made to his parents from the offices of Russia’s Investigative Committee, a law enforcement agency, when he told them he was under investigation.

Independent lawyers – from both Russia and Ukraine – have not had any access to Butkevych himself or to the case files in the investigation against him.

“I did not participate in the trial, I did not see Butkevych and I have not seen the case files,” said Russian lawyer Leonid Solovyov, who tried to locate Butkevych in Luhansk.

Oleksander Pavlichenko, executive director of the Ukrainian Helsinki Human Rights Union, an umbrella organisation for human rights groups in Ukraine, said the Butkevych case is an example of how Russia is using war crimes legislation “against its enemies”.

According to Russian media, the authorities in Luhansk have launched more than 1,000 investigations into breaches of the customs of war against Ukrainian military personnel in 2022.

“Russia is trying to imitate the observance of judicial procedures, as well as the existence of a system of law in the occupied territory,” Pavlichenko said.

Butkevych is a prisoner of war, the Ukrainian rights defender said, so under the Geneva Conventions he should be released and returned to Ukraine in a POW exchange, rather than sent to prison.

The Investigative Committee claimed Butkevych purposefully sought to kill two civilians on Severodonetsk’s Gagarin Street on 4 June 2022, while his unit was fighting in the city.

According to a report from the Investigative Committee and Russian newspaper Kommersant, Butkevych allegedly injured a mother and daughter at the entrance to their apartment block after firing an anti-tank grenade launcher at them.

Investigators questioned the two victims, who said they had heard shells exploding nearby and decided to take refuge under the front stairs inside the building. At around 5pm, there was an explosion in front of the entrance to the building. Both women were wounded in the legs by shrapnel.

The Investigative Committee’s description of the women’s testimony suggests they could not see who had caused the explosion.

The Committee claims that Butkevych admitted his guilt. Graty said they could not confirm this.

However, according to Graty, Butkevych spent the first two weeks of June 2022 in Kyiv and the surrounding region, some 700 kilometres from Severodonetsk.

“According to my communications with Maksym, I have not the slightest doubt that he was not in Severodonetsk on 4 June,” said Ukrainian human rights activist Sasha Fainberg. “He was in touch every day. That is impossible when there’s fighting going on.”

“Moreover, when his unit was sent on any mission, he warned that he would not be in touch for some time. Which, in fact, happened several times – once in April, and then on 19 June,” Fainberg added.

In the correspondence – which openDemocracy has seen – Butkevych told his friends that his unit, the Berlingo special battalion, was moving from the city of Poltava in central Ukraine towards the frontline in the east on 14 June, some 10 days before the alleged incident in Severodonetsk. He was later taken prisoner in Hirske, just outside the city.

Russian forces have captured thousands of Ukrainian service personnel and civilians in the course of its year-long invasion of the country. While the two countries have exchanged some prisoners of war, the process is slow and thousands of Ukrainian families are still waiting for news of their loved ones.

Following Butkevych’s conviction, two other captured Ukrainian soldiers, Vladyslav Shel and Viktor Pokhozei, were also found guilty of alleged war crimes offences – this time by a court in the self-proclaimed ‘Donetsk People’s Republic’. Graty was unable to confirm any of the charges against them.

22 March: editors corrected the last received message from Maksym Butkevych to his father, Oleksandr Butkevych.