The Kremlin on Friday said that at least three Russians freed in a landmark prisoner exchange were undercover Russian agents, a rare public admission into the work of Moscow's top-secret security services.
Moscow said Vadim Krasikov -- who was serving life in prison in Germany for the 2019 brazen murder of a former Chechen separatist commander in broad daylight in a Berlin park -- was an elite operative with Russia's FSB security agency.
Krasikov was one of the central figures in Thursday's historic multi-country exchange, with Putin having publicly lobbied for his release in a bid to get the deal over the line in the face of hesitation from Berlin.
The Kremlin almost never reveals details about its sprawling intelligence agencies, but it confirmed Friday that at least two others freed in the deal were also long-term undercover agents stationed in the European Union.
Russian President Vladimir Putin has portrayed them as returning heroes, personally thanking them for their service to the "Motherland" and promising to shower them with state awards.
"Krasikov is an FSB employee," Kremlin spokesman Dmitry Peskov told reporters on Friday.
An investigation by Bellingcat had previously revealed his links to the agency, though Friday's admission was the first time Moscow has publicly confirmed he was a state operative.
Peskov said Krasikov served in the agency's elite and secretive "Alpha" unit alongside people who went on to be Putin's personal bodyguards.
German Chancellor Olaf Scholz admitted Thursday that releasing Krasikov -- who German judges said had carried out the assassination on orders from Moscow -- was "not easy."
In return, Berlin secured the release of five German nationals -- including some with dual Russian citizenship.
Russia also released three US citizens -- journalists Evan Gershkovich and Alsu Kurmasheva, as well as ex-marine Paul Whelan -- and some of the country's most prominent domestic dissidents in a deal heralded by US President Joe Biden as an historic "feat of diplomacy."
Peskov also confirmed that a Russian couple released from Slovenia were also spies.
Artem Dultsev and Anna Dultseva, whose two children were sent to Russia in the deal, had been posing as an Argentine couple that ran an IT businesses and art gallery in Ljubljana.
"The children of the illegals who arrived yesterday only found out they were Russian on the plane from Ankara. They do not speak Russian," Peskov said.
"Illegals" is a term used to refer to Russian undercover spies who live in foreign countries for years, even decades, under fake identities, gathering intelligence to send back to Moscow.
Putin had greeted the children with "buenas noches" -- Spanish for "good evening" -- after their arrival on Thursday.
"They didn't even know who Putin was. That's how illegals work, making such sacrifices for the sake of their work and their dedication to their service," Peskov said on Friday.
At Moscow's Vnukovo airport on Thursday, Putin had told those released: "The Motherland never forgot about you."
To secure their return, the Kremlin leader agreed to release not only the three US citizens, but some of his fiercest domestic critics who had been jailed for campaigning against him.
"I was sure I'm going to die in prison," said opposition politician Vladimir Kara-Murza, sentenced to 25 years on "treason" and other charges.
He and two other freed Russian opposition politicians -- Ilya Yashin and Andrei Pivovarov -- announced a press conference in Bonn on Friday evening.
In the United States, the three freed US citizens touched down in Texas on Friday for medical checks after earlier landing at Joint Base Andrews, just outside Washington.
Their arrival on US soil late Thursday was met by cheers from family and friends as they disembarked a plane, before each embracing Biden and Vice President Kamala Harris.
"It feels wonderful, it was a long time coming," Biden told reporters.
In total, 24 prisoners were freed -- eight by the West, 15 by Russia and one by Russia's ally Belarus.
In emotional scenes at the air base, Wall Street Journal reporter Gershkovich was filmed embracing and lifting his mum into the air as they reunited after 16 months in captivity.
"I'm glad I'm home. I'm never going back there again," Whelan laughed.
The United States had denounced the charges against them -- Whelan and Gershkovich for "espionage" and Kurmasheva for spreading "false information" about Russia's military -- as baseless.
