Ukraine on Saturday extradited one of the men suspected of plotting to assassinate President Vladimir Putin, state-owned Channel One reported.
Ilya Pyanzin, who was arrested in Odessa in February, had already been taken to Moscow, the channel said, showing him at Odessa airport and then aboard a plane in handcuffs.
"Now Pyanzin will await trial in one of the Moscow jails," the report said.
The alleged plan to bomb Putin's motorcade was disclosed on Russian state television just days before the March 4 presidential election and was quickly dismissed by critics as a Kremlin effort to drum up support for the Russian leader.
Pyanzin and a second arrested suspect, a Chechen Adam Osmayev had been held in jail for allegedly plotting to kill the Russian leader who was was re-elected in the March ballot to a third presidential term.
State television channels have broadcast apparent confessions admitting that they were acting on the orders of Islamist militants.
Osmayev, who is the alleged leader of the plot, is still in the Odessa jail, having asked the European Court of Human Rights to rule on the legitimacy of Russia's extradition request.