Russia's top security agency on Monday identified a second Ukrainian that it alleged was involved in the killing of the daughter of a Russian nationalist ideologue.

Russia's Federal Security Service (FSB), the main KGB successor agency, said that Ukrainian national Bogdan Tsyganenko helped prepare the killing of Darya Dugina, the daughter of Alexander Dugin, who was described by some in the West as "Putin's brain."

The FSB charged that Tsyganenko provided the main suspect, Natalya Vovk, with a fake ID and fake license plates, and helped her assemble an explosive device that was planted in Dugina's car.

Tsyganenko, 44, arrived in Russia via Estonia on July 30 and left the country the day before the killing, the FSB said.

Dugina, a 29-year-old commentator with a nationalist Russian TV channel, died when a remotely controlled explosive device planted in her SUV blew up on the night of Aug. 20 as she was driving on the outskirts of Moscow, ripping the vehicle apart and killing her on the spot, authorities said.

Both she and her father, who is a philosopher, writer and political theorist, ardently supported Russian President Vladimir Putin's decision to send troops into Ukraine.

The FSB said Dugina's killing was "prepared and perpetrated by the Ukrainian special services" and accused Vovk of carrying out the killing and then fleeing to Estonia.

Vovk, according to the FSB, arrived in Russia in July with her 12-year-old daughter and rented an apartment in the building where Dugina lived in order to shadow her. The agency alleged that Vovk and her daughter were at a nationalist festival that Dugin and his daughter attended just before the killing.

The FSB said Vovk used a license plate for Ukraine's Russian-backed separatist Donetsk region to enter Russia and a Kazakhstan plate in Moscow before switching to a Ukrainian one to cross into Estonia. It released video and photos of the suspect from surveillance cameras at the border crossings, while driving the car in Moscow and at the entrance to the Moscow apartment building.

The agency said Monday that Tsyganenko provided Vovk with a Kazakh license plate and Kazakh ID documents belonging to a real person named Yulia Zaiko. It didn't offer any details as to how Vovk obtained other license plates and whether those were fake, too.

Kyiv has vehemently denied any involvement in Dugina's death. Estonian authorities said they have not received any formal requests or inquiries from Russia regarding Vovk.