Yuri Ivanovich Modin (8 November 1922 in Suzdal[1] – 2007 in Moscow[2][3]) was the KGB controller for the "Cambridge Five" from 1948 to 1951, during which Donald Duart Maclean was said to have passed atomic secrets to the Soviets. In 1951, Modin arranged the defections of Maclean and Guy Burgess. Modin's predecessors in control of the damaging Cambridge spy ring were executed during Stalin's Great Purge.
Modin said of Kim Philby in February 1994:
He never revealed his true self. Neither the British, nor the women he lived with, nor ourselves [the KGB] ever managed to pierce the armour of mystery that clad him. His great achievement in espionage was his life's work, and it fully occupied him until the day he died. But in the end I suspect that Philby made a mockery of everyone, particularly ourselves.[4]: 270
In his 1994 book, Modin revealed that in the early days Moscow did not really trust the Cambridge Five, British agents who were passing secret information to the Soviet Union. The KGB had difficulty believing that the men would have access to top secret documents; they were particularly suspicious of Philby, wondering how he could have become an agent given his Communist past. According to a review of Modin's book, "the center concluded that all five must really be British intelligence officers trying to penetrate the KGB".[5]