Russia's intelligence agency claimed to have foiled an assassination attempt on Margarita Simonyan, the chief editor of broadcaster RT, on Saturday.
The Federal Security Service (FSB) said the Kyiv secret service (SBU) paid a Russian neo-Nazi to kill Simonyan, a fervent supporter of Moscow's war on Ukraine, and a leading television presenter, Ksenia Sobchak.
RT published a video showing a young man wearing a T-shirt saying Waffen SS, claiming Ukrainians had told him to carry out the killing.
The man, 18, gave his name and date of birth before describing the planned crime. He said security officials arrested him as he prepared to hand over some weapons.
The Russian secret service frequently reports on alleged attacks supposedly planned by Ukrainian intelligence services. These claims cannot be independently verified.
However, other backers of the Kremlin's war have been killed in the past, such as well-known military blogger Vladlen Tatarsky who died in an explosion in a St Petersburg café in April.
Last August, Darya Dugina – daughter of the right-wing nationalist ideologue Alexander Dugin – was killed in a car bombing near Moscow.
In May, prominent Russian writer Zakhar Prilepin was seriously injured in another car bombing.
Simonyan, who is also editor-in-chief at the news agency Rossiya Segodnya, thanked the secret service for saving her life.
According to the FSB, "members of the neo-Nazi group Paragraph-88" were arrested in Moscow and the Ryazan area after searches at their homes and offices.
A Kalashnikov machine gun plus 90 cartridges, knives, truncheons, computers and Nazi flags and literature were seized from the suspects, the FSB said.
The party who allegedly ordered the attack was said to have been willing to pay 1.5 million roubles ($16,600 million) for each murder.
