In April 2022, two months after Russia invaded Ukraine, a man in his thirties called Victor Muller Ferreira flew into Amsterdam airport using a Brazilian passport. He was identified by the Dutch authorities as Russian national Sergey Vladimirovich Cherkasov and immediately sent back to Brazil, where investigations by both the FBI and the Brazilian police identified him as a Russian intelligence officer. He had been living in Brazil, undercover, for years, with a well-developed personal 'legend', or cover story, that included a passion for Forró, a popular Brazilian partner-dance. Cherkasov is currently serving a five year prison sentence in Brazil for identity fraud, and Russia demands his extradition.

Leandro Prazeres of BBC News Brazil - who happens to be a big fan of Forró himself - and BBC Russian's Olga Ivshina unpack the story of this 'fake Brazilian' and explore the history and motivations of Russia's network of so-called 'illegals', or deep cover spies.

This episode of The Documentary comes to you from The Fifth Floor, the show at the heart of global storytelling, with BBC journalists from all around the world.

Produced by Laura Thomas, Caroline Ferguson and Hannah Dean.

(Photo: Irena Taranyuk.)