May 9 (UPI) -- The Islamic State has released a video purportedly showing the beheading of Evgeny Petrenko, a captured Russian intelligence officer in Syria.
The SITE Intelligence Group, which monitors extremist propaganda, on Tuesday said the Islamic State released the Russian-language video through its affiliated Furat Media outlet. In the video released Monday, the Islamic State boasts about recent success against Russian forces in Syria.
Russia's Ministry of Defense rejected the video's authenticity, stating all Russian service members in Syria are alive and accounted for, The Moscow Times reported.
In an interview apparently given under duress, Petrenko said he was a Russian Federal Security Service agent prior to capture and had been abandoned by the Russian government. He also called on Russia to end its military efforts in Syria.
Petrenko said he was ordered to infiltrate the ranks of Omar al-Shishani, a Georgian Chechen commander for the Islamic State in Syria believed to have been killed last year. The U.S. Department of Defense previously identified Shishani as the Islamic State's "Minister of War."
"I was supposed to infiltrate the special services of the caliphate and the leadership of the caliphate," Petrenko said in the video. "One of my orders was to gain access to Omar al-Shishani or to his circle. But during this I was discovered and arrested by the security services of the caliphate."
An Islamic State militant later beheads the man who SITE identified as Petrenko, 36.