A British national has reportedly been captured by Russia’s forces in the Kursk region while fighting for Ukraine.

In a video posted on pro-war Russian Telegram channels on Sunday, a man wearing combat fatigues identifies himself as 22-year-old James Scott Rhys Anderson from the UK.

The man, speaking with an English accent, says that he served as a signalman in the British army until 2023 before joining the International Legion in Ukraine to fight against Russia.

In the footage, which has not been verified, the captured man appears with his hands tied. It is unclear when the clip was recorded.

Since the Ukrainian president, Volodymyr Zelenskyy, issued a call in February 2022 for foreigners to join the fight, thousands of people from around the world have travelled to Ukraine. Many have joined units like the International Legion, known as the most selective of the foreign groups and operating as part of a military unit within the Ukrainian ground forces.

Yuri Podolyaka, a popular pro-Kremlin military blogger, wrote on Telegram that Anderson was captured near the village of Plekhovo in Russia’s Kursk region.

Russia usually claims that the foreign fighters it has captured are mercenaries and are not entitled to protection as prisoners of war under international law.

The UK Foreign Office said it was “supporting the family of a British man following reports of his detention”.

The Ministry of Defence has declined to comment at this stage.

Russian forces have been battling Ukrainian troops in the Kursk region since 6 August, when Kyiv surprised Moscow with the biggest foreign attack on Russian soil since the second world war and subsequently seized 100 villages over an area of more than 1,300 sq km.

On Sunday, Reuters reported that Ukraine had lost more than 40% of the territory it initially captured in the Kursk region after Russian forces, bolstered by 11,000 North Korean troops, launched a wave of counter-offensives.

In the summer of 2022, two Britons captured while fighting in Mariupol as members of Ukraine’s marines were sentenced to death following a show trial in a court in Russian-occupied eastern Ukraine.

The men were later released as part of a prisoner swap between Russia and Ukraine that was brokered by Saudi Arabia.