In 2005, Sulim Yamadayev was named a Hero of Russia, Russia's top honour
The Russian authorities have confirmed a prominent opponent of the pro-Kremlin Chechen President, Ramzan Kadyrov, was shot dead in Dubai on Saturday.
Diplomats said Sulim Yamadayev's body had been identified by his relatives.
Mr Yamadayev fell out with Mr Kadyrov last year and was sacked as commander of an elite security forces battalion.
Saturday's killing is the fourth of a prominent Chechen since September, when Mr Yamadayev's brother Ruslan was shot dead while driving in central Moscow.
The Chechen leader has denied any involvement in the killings.
Russia is poised to declare a formal end to its 10-year war in Chechnya this week, says the BBC's Rupert Wingfield-Hayes in Moscow.
But far beyond its borders, the bloody struggle for control of Chechnya continues, our correspondent adds.
On Saturday, Dubai police said a 36-year-old Chechen man had been shot in the underground car park of a luxury residential complex. It took some time to confirm that the victim was Sulim Yamadayev.
Mr Yamadayev was shot dead in an underground car park in Dubai
"I just received confirmation from the Dubai police that he was killed," Russian Consul Sergei Krasnogor told the Reuters news agency on Monday.
The Yamadayevs came from of one of the most powerful clans in Chechnya.
Sulim was a former separatist rebel leader who later switched to the Russian side, after then-President Vladimir Putin sent troops to Chechnya to retake control.
Mr Yamadayev became commander of the elite Vostok security forces battalion, a unit of former rebels who have helped quell separatist resistance. In 2005, he was named a Hero of Russia, the top national honour.
But last year, he was dismissed after falling out with Mr Kadyrov and later fled to the United Arab Emirates.
Spate of killings
Recently opponents have accused Mr Kadyrov's henchmen of systematically removing any opposition to his absolute rule, our correspondent says.
However, Mr Kadyrov and his Moscow-backed government have denied any connection to the recent killings of several high-profile Chechens.
In January, Umar Israilov, a former bodyguard for Mr Kadyrov who had accused him of torture and kidnapping, was shot dead on a street in Vienna. Then last month, a former deputy mayor of Grozny was shot dead in Moscow.
In 2004, two Russian intelligence agents were convicted of killing a former Chechen president, Zelimkhan Yandarbiyev, in the nearby state of Qatar.
Chechnya has been devastated by heavy fighting since 1994, when Russian troops first poured in to crush a separatist movement.