ISTANBUL

An outspoken critic of veteran Tajik leader Imomali Rakhmon has been shot dead by an unknown assailant on a street in Istanbul.

Umarali Kuvvatov, who had been living in exile in Turkey and was head of the Group 24 opposition movement, was killed with a single shot to the head late on Thursday night.

Turkey's anti-terrorism police unit and murder squad are handling the investigation into the killing of the 47-year-old businessman.

Mr Kuvvatov had accused President Rakhmon, a 62-year-old former head of a Soviet state farm who has governed the impoverished Central Asian republic since 1992, of rampant corruption and nepotism.

Mr Kuvvatov had worked for a business of one of Mr Rakhmon's close relatives. He took to politics after he fell out with Mr Rakhmon's clan due to an apparent clash of business interests, said Alexander Knyazev, a Kazakhstan-based Central Asia analyst.

A Turkish newspaper quoted people close to Mr Kuvvatov as saying he and his family may have been poisoned before he was shot. It said the assailant was believed to be Tajik and had said a few words before opening fire.

A spokesman for the Tajik prosecutor-general's office said it had information about the killing but gave no details.

Last October, Mr Kuvvatov appealed via social networks for an open-ended protest in the Tajik capital Dushanbe to topple Mr Rakhmon and his government. But people did not show up and the authorities increased the police presence in the city and briefly blocked some social media.

Mr Kuvvatov's Group 24 movement was then declared an "extremist organisation" and banned by Tajikistan's Supreme Court.

Tajikistan wanted him for a number of crimes, including extremism, economic crimes and hostage-taking.

Mr Kuvvatov had lived in Russia and the United Arab Emirates before moving to Turkey. Turkey had refused a Tajik request to extradite him.