Yuri Klementiev was the financier of arms dealer Mikhail Fjodorov.
While investigating missing bootleg Starktech from Hammer Industries, S.H.I.E.L.D. Agent Natasha Romanoff infiltrated Klementiev's yacht in Sochi, Russia, after obtaining information about its location from her then-rival Sofia.
Romanoff went undercover as international model Marya Konn at a party inside the yacht, when she came across Klementiev, who tried to seduce her, thinking she was one of the models he is used to have on his boat, but she quickly dismissed him.
After that, Natasha approached fellow agent Gennady Markov, who had been posing as one of Klementiev's bodyguards for weeks, and obtained information to try to locate the technology.