He has left me feeling violated, says Sotheby's boss conned out of £800,000 by lover posing as a Goldman Sachs billionaire

• Alistair Stewart, 53, pretended he was running a hedge fund in Switzerland
• Harvard-educated Nina Siegenthaler fell for his sophisticated charms
  
• Miss Siegenthaler told court Stewart is a 'cunning predator'
• Stewart jailed for five-and-a-half years at Old Bailey
  

By Tom Kelly

PUBLISHED: 11:57 EST, 19 December 2012 | UPDATED: 19:57 EST, 19 December 2012

Smooth criminal: Cambridge dropout Alistair Stewart seduced a wealthy woman out of more than £600,000 by posing as a retired Goldman Sachs billionaire

A Sotheby's executive yesterday told how she felt ‘violated’ after being seduced out of £800,000 by a benefits-claiming conman posing as a Goldman Sachs billionaire.

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.’

She pre-recorded the message which she felt unable to deliver in person in court because she was still too ‘shocked and traumatised’ to see him in the flesh.

Victim: Nina Siegenthaler, a Sotheby's executive, fell in love with Stewart before he defrauded her

She said: ‘His insatiable desire to dupe leaves a path of destruction in its wake.

‘I experienced a profound sense of violation on many levels.’

Stewart targeted her by pretending to be interested in buying two properties worth more than £10million in the Caribbean tax haven of the Turks and Caicos Islands where Miss Siegenthaler is vice-president of Sotheby’s International Realty.

After catching her at a vulnerable time during the breakdown of her marriage to the father of her young daughter, he spent six months grooming her on Skype, during which time she fell in love with him.

Violated: Nina Siegenthaler said Stewart '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.'

Luxury: Hartling House, a 9,000-square foot villa on the island of Providenciales, which Stewart, posing as a retired Goldman Sachs millionaire, pretended he wanted to buy

She also agreed to let him ‘invest’ her life savings after he said her daughter’s future would be in jeopardy if she refused.

After receiving the cash, he flew to visit her – on a £4,800 first class plane ticket – and bought her a £31,000 watch as a gift.

She described him as ‘completely convincing’, adding: ‘I never met someone who could fabricate so proficiently.

Home: The housing association block of flats in Burgess Hill, West Sussex where Stewart lived while pretending to run a hedge fund in Switzerland

‘He told detailed stories about his alleged tenure with Goldman Sachs. None of it was true.’ He also invented a wife who had tragically died, a fictional daughter, and lied that he  had leukaemia.

But after finally becoming suspicious, she investigated and discovered he had previously been convicted of four charges of fraud, including fleecing a 73-year-old woman out of £27,000.

When she confronted him he told her: ‘I lie as easily as I breathe.’

Nathaniel Rudolf, defending, said Stewart had repaid the £92,470 that was left of the money.