MOSCOW -- The mayor of a Russian city in a North Caucasus republic has been arrested on charges of murdering an investigator, law enforcement authorities said Saturday.

Said Amirov, mayor of Makhachkala, capital of the Dagestan republic, was accused of organizing the murder of a criminal investigator, Russia's Investigative Committee spokesman Vladimir Markin told reporters.

Investigators said that Amirov organized in December 2011 the murder of Arsen Gadzhibekov, acting head of the committee's local branch in the city.

The mayor has been sent to Moscow, Markin said, adding more than 10 suspected accomplices involved in the crime have also been detained.

Earlier, local media reported that Amirov was detained on suspicion of complicity in a series of grave crimes.

Amirov served as deputy prime minister of Dagestan from 1991 to 1998. He had been on the mayoral position since 1998.