• Journalist Darya Dugina, aged 29, died on Saturday when a vehicle she was driving exploded near Russia's capital.
• Her prominent ultra-nationalist father, Alexander Dugin, said to be close to Mr Putin, may have been the intended target of the attack.
Russia has accused Ukrainian special services of killing the daughter of one of Vladimir Putin's allies in a car bombing near Moscow at the weekend.
Journalist Darya Dugina, aged 29, died on Saturday when a vehicle she was driving exploded near Russia's capital.
Her prominent ultra-nationalist father, Alexander Dugin, said to be close to Mr Putin, may have been the intended target of the attack.
Ukrainian officials have denied any involvement in the explosion.
But Russia's Federal Security Service (FSB) said on Monday it had solved the case and said that Ukraine was directly responsible.
The FSB told Russian media that a Ukrainian woman had moved to Russia in July alongside her young daughter - but that she was in fact a Ukrainian special services contractor.
The woman, it said, rented an apartment in the same building as Ms Dugina for a month, preparing for the attack. In that time, she allegedly followed the journalist through Moscow in a Mini Cooper - for which she used three different licence plates.
The suspect then escaped to Estonia after the explosion, the FSB said.
An advisor to Ukraine's President Zelensky, Mykhailo Podolyak, said the FSB's version of events was "Russian propaganda" from "a fictional world".
Ms Dugina and her father were attending a festival near Moscow on Saturday evening where Mr Dugin, a philosopher, gave a lecture. They had reportedly intended to leave in the same car, but changed their plans at the last minute.
Investigators said explosives had been planted underneath the Toyota Land Cruiser Ms Dugina was driving.
Video from the scene posted online appeared to show a shaken Mr Dugin watching emergency services attend the burning vehicle.
A family friend, Konstantin Malofeev, published a statement on behalf of Mr Dugin which branded his daughter's killing "a terrorist act by the Ukrainian Nazi regime".
He was referencing the unfounded yet oft-repeated claim by Russian leadership of a powerful Nazi presence inside Ukraine - one of the main reasons put forward for the invasion.
"My daughter Darya Dugina was brutally murdered in front of me," the statement on Telegram read. "She was a beautiful Orthodox woman, patriot, war reporter, an expert for central TV and philosopher."
"We only need our victory. My daughter sacrificed her young woman's life to its altar. So please, achieve it!"
Ms Dugina was a vocal supporter of the Russian invasion of Ukraine. She had been placed under sanctions by the UK in July as "a frequent and high-profile contributor of disinformation in relation to Ukraine".
Her father, Alexander, is also known as "Putin's brain" and has long expressed an anti-Western, ultranationalist philosophy that has made him a significant figure in Moscow - despite holding no political office himself.
Seen as the founder of Russia's anti-European movement, he told the BBC in 2014 that war with Ukraine "is inevitable", and had long called for the annexation of Crimea - something which happened that year.
President Putin personally paid tribute to Ms Dugina in a statement from the Kremlin on Monday.
"A vile, cruel crime cut short the life of Darya Dugina, a bright, talented person with a true Russian heart: kind, loving, sympathetic and open," he wrote.
"Journalist, scientist, philosopher, and war correspondent, she honestly served the people and the fatherland, and proved by deed what it means to be a patriot of Russia."