Artem and Anna Dultsev were undercover intelligence officers commonly known as "illegals." They were posing as Argentine expats when they were arrested in Slovenia.

The children of two Russian intelligence agents, who were among the detainees released as part of a historic prisoner swap, only discovered their nationality when they were being flown to Moscow, the Kremlin said Friday.

Anna and Artem Dultsev, spies posing as Argentine ex-pats living in Slovenia, were returned to Russia with their children, ages 8 and 11, who do not speak Russian.

The Dultsev children thought they were Argentinian all their lives, cannot speak Russian and did not know who was President Putin.

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 children of deep cover Russian spy intelligence unit agents, who were among the detainees released as part of the biggest East-West prisoner swap since the cold war, only discovered their actual nationality after their flight took off for Moscow,

The Russian sleeper agents, who operated under the aliases Ludwig Gisch and Maria Rosa Mayer Muños, had lived in Slovenia since 2017 posing as Argentine expats.