How did MI5 miss the Oxford housewife beaming our nuclear secrets to Stalin? BEN MACINTYRE reveals how a Soviet agent delighted her masters with access at heart of Britain's top-secret atom bomb research
BEN MACINTYRE: When housewife and mother Ursula Beurton (pictured with her children in 1945) - in reality, Major Ursula Kuczynski of the Red Army, a Soviet spy who had conducted espionage operations in China, Poland and Switzerland - landed at Liverpool on a ship from Spain in early 1941, MI5 already had its suspicions about her. Her parents and siblings, living in exile in London having fled as refugees from Germany, were known to the security services for their openly Leftist views, while husband Len was black-listed because he'd fought in the Spanish Civil War and had 'a communistic smell' about him.
