Question: William John Christopher Vassall, was a British civil servant who spied for the which government nation, under pressure of blackmail from 1954 until his arrest in 1962, the Vassall scandal greatly embarrassed the Macmillan government, but was soon eclipsed by the more dramatic Profumo affair, was a British political scandal that originated with a brief sexual relationship in 1961 between John Profumo, the Secretary of State for War in Harold Macmillan's government, and Christine Keeler, a 19-year-old would-be model?
Sentence (from "John Vassall"): Although operating only at a junior level, he was able to provide details of naval technology which were crucial to the modernising of the Soviet Navy.
Relevant evidence: No