Russian President Vladimir Putin welcomes Russian nationals, including Artyom Dultsev, Anna Dultseva and their children, following a prisoner exchange between Russia with Western countries, during a ceremony at Vnukovo International Airport in Moscow, Russia August 1, 2024

MOSCOW, Aug 2 (Reuters) - A family of Russian sleeper agents flown to Moscow in the biggest East-West prisoner swap since the Cold War were so deep under cover that their children found out they were Russians only after the flight took off, the Kremlin said on Friday.

“Before that, they didn’t know that they were Russian and that they had anything to do with our country,” Kremlin spokesman Dmitry Peskov told reporters.

“And you probably saw that when the children came down the plane’s steps that they don’t speak Russian and that Putin greeted them in Spanish. He said ‘buenas noches’.”

Giving new details about the swap and those freed, Peskov confirmed that Vadim Krasikov, a hitman released by Germany, was an employee of Russia’s FSB security service and had served in Alpha Group, the FSB’s special forces unit.

Krasikov was convicted by a German court of killing a former Chechen militant in a Berlin park in 2019. President Vladimir Putin hugged him after he got off a plane in Moscow on Thursday evening.

Krasikov, wearing a baseball cap and a tracksuit top, was the first of the returnees to disembark the plane and meet Putin, signalling his importance to Moscow, which prides itself on bringing home intelligence operatives arrested abroad.

Among those released were the so-called “illegal” sleeper agents - the Dultsevs, a husband and wife convicted a court in Slovenia of pretending to be Argentinians in order to spy, who were flown back to Russia with their two children.