Turkish police think a hit squad working for the Russian government was behind the assassination of three Chechens in Istanbul three weeks ago.
The victims – including Berg-Khadzh Musayev, a high-ranking member of Russia's Caucasus Emirate terrorist movement – were shot in broad daylight on 16 September in a scruffy suburb on the European side of Istanbul.
The assassinations bring the number of Chechens killed in the Turkish city to six in three years. They fit into a pattern of killings in cities across the world targeting Chechens who have opposed the Kremlin-backed regime of Ramzan Kadyrov.
Turkish police suspected the hand of Russian special forces in the previous killings in Istanbul, but the murderers were so professional that they left no trace behind. This time, however, the killers came within a whisker of being caught, leaving clues that seem to point to a hit organised within Russia, carefully planned, and carried out by a number of professional agents.
Russian authorities have made no official comment on the killings, but a law signed in 2006 by Vladmimir Putin, who was then President and is now Prime Minister, authorises Russian secret services to kill "terrorists" abroad.
Turkish police have so far made no public allegations or demands to Russia, but a source close to the investigation told The Independent that police had little doubt that the hit was carried out by Russian agents. They believe a team of eight or nine agents entered Turkey one by one in the two weeks before the attack. Most managed to leave the country afterwards.
Much of the background to the triple killing is still murky, but The Independent has been able to piece together details about the movements of the assassins in the run-up to the murder.
Police have retrieved a passport in the name of Alexander Zharkov, 55, whom they believe to be the organiser of the group, but they do not know if he has left the country under another identity or is still at large.
They also believe that a Chechen, Ziyauddin Makhayev, may have connections with the group. Mr Makhayev has been pictured with Chechnya's pro-Kremlin President Kadyrov, and was known to the Chechen community in Istanbul as an envoy of Mr Kadyrov. However, a spokesman for the President has denied that the two were close.
Andrei Soldatov, a leading Moscow-based analyst of the Russian security services, said it was "quite possible" that Russia was behind the killing. The murders bring to mind the assassination of Zelimkhan Yanderbiyev, the former Chechen Vice-President, in Qatar in 2003. Qatari authorities arrested two Russian military intelligence agents and the First Secretary of the Russian Embassy in Qatar over the killing.
"Historically, countries use this kind of killing to wipe out militants, but also to change the position of the countries where the assassinations take place," Mr Soldatov says. "History shows that often, after this kind of attack, instead of getting angry, the countries become more amenable to demands."
About 2,000 Chechens live in Istanbul. More than 100 have arrived in the past year alone, many of them fighters with Caucasus Emirate, according to sources in the Chechen community. Russia believes that a large part of the movement's finances is managed from Turkey.