A video circulated on social media on December 2 appears to show an Islamic State (IS) militant beheading an alleged Russian spy captured in Syria.
The 7 1/2-minute video shows the victim sitting in an orange jumpsuit confessing in Russian to his recruitment by the Russian Federal Security Service (FSB).
The man identified himself as Magomed Khasayev and said that he was ordered by Russian intelligence to travel to Syria and identify fighters who seek to return to Russia's Caucasus region to carry out attacks. He said he had lived in Chechnya before that.
Russia's Caucasus region has been besieged by Islamist insurgencies for two decades, including two full-scale wars in Chechnya. The IS has reportedly recruited thousands of fighters in the Caucasus.
In the IS video, which was subtitled in Arabic, Khasayev said he had been in Syria since August 2014. It was not immediately clear when he was captured by IS.
After Khasayev speaks, he is shown in a different setting on a beach with a Russian-speaking militant, who addresses Russian President Vladimir Putin and asserts that Russian forces will be defeated.
Brandishing a large knife, the militant then appears to behead Khasayev.
The video could not be independently identified but it bears the logo of IS's media office in the Syrian province of Raqqa. It is the first from IS concerning alleged Russian spies since Russia began hitting the extremist group and other insurgents with air strikes in Syria on September 30.
In January, IS released a video purporting to show a young boy shooting dead two men accused of working for Russian intelligence services.
There was no immediate comment from Russia's Foreign Ministry or its FSB security service.