Harvard-educated Nina Siegenthaler, 37, fell for the sophisticated charms and 'A-list acting skills' of former Charterhouse schoolboy and Cambridge University drop-out Alistair Stewart.
She branded him a sociopath and said she had believed his 'countless lies' about being a hedge fund manager with properties worldwide.
She gave him her £630,000 life savings to invest, plus £154,000 for him to rent a luxury home for them in the Caribbean.
In reality, Stewart was orchestrating his fraud from a council flat in Burgess Hill, West Sussex, where he lived for most of the time on incapacity benefits.
He blew almost all her cash in four months on a £55,000 Mercedes, private jets, stays at the Ritz and Hyde Park Tower hotels, chauffeur-driven shopping trips to Harrods and jaunts in helicopters.
Yesterday, as 53-year-old Stewart was jailed for five-and-a-half years at the Old Bailey, Miss Siegenthaler called him a 'cunning predator'.
She said: 'He is one of the most intelligent, charismatic and seemingly generous people I have met.
'He is also a cunning predator, a man without conscience or moral compass. His ultimate aim is not to rob, though he certainly will do that, but to control and manipulate.'
Comment: According to Dr. Robert Hare, hundreds of thousands of psychopaths live and work and prey among us. Your boss, your boyfriend, your mother could be a "subclinical" psychopath, someone who leaves a path of destruction and pain without a single pang of conscience.
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