Turkey's state-run news agency says a Tajik businessman and opposition figure has been shot dead in Istanbul.

Anadolu Agency said Friday Umarali Kuvvatov was killed by a friend in the street late Thursday after the two got into an argument. The private Dogan news agency, however, said that a third man approached the two and shot Kuvvatov in the head. Both the assailant and the friend escaped.

Kuvvatov was formerly in President Emomali Rakhmon's inner circle but fell out of favor in 2012 and fled Tajikistan.

Tajikistan's government in January asked Turkey to extradite Kuvvatov so that he could face charges of fraud and provoking political unrest.

Kuvvatov channeled his anti-government activities through Group 24, a movement that existed largely online and loosely united disparate critics of Rakhmon's regime.