Mussayev is not the first former KGB officer to make such a claim. Years ago, Yuri Shvets, a former KGB major now living in Washington, D.C., was a key source for Craig Unger’s book American Kompromat: How the KGB Cultivated Donald Trump, and Related Tales of Sex, Greed, Power, and Treachery. Shortly after Mussayev’s recent statement, another ex-KGB officer, Sergei Zhyrnov, who now resides in France, endorsed the claim in an interview with a Ukrainian journalist.