‘It never occurred to me that I was living with a liar’

Miss Boss was speaking at the trial of her former husband, who is accused of kidnapping their seven-year-old daughter Reigh last summer.

The Kensington-based management consultant earned £1.2 million a year but said she was "pretty stupid" not to realise her husband of 12 years was not a Rockefeller with a billion-dollar art collection, as he claimed, but a German conman called Karl Gerharstreiter.

"It never occurred to me that I was living with someone who was lying to me. I was focused on getting enough to eat and looking after my daughter, I didn't have time to worry about it," Miss Boss told the court in Boston.

Miss Boss, 42, met her future husband in 1993 and they were married in 1995. The relationship progressed from initial romance — "he spent a lot of money on me, he was always generous, and well-dressed" — to a marriage characterised by intimidation, emotional abuse and virtual imprisonment.

She said he never had a job, was 18 hours late for their daughter's birth, and then named the child without consultation. Miss Boss told the court she often woke up hungry in a cold house because her husband — who insists on being addressed as Mr Rockefeller by his lawyers — controlled their bank accounts and would only heat the side of the house where he slept.

Miss Boss told the court she never questioned him, despite mounting inconsistencies. She said she was fooled into believing her husband's elaborate claims and didn't dare confront him because he would threaten to take sole custody of their daughter.

"You mistakenly confuse money with power," she said. "Power in a relationship goes far beyond money."

Gerharsteiter has claimed insanity as a defence. But some observers say Miss Boss is as much the victim of her own fantasies as his.

"It's pretty obvious that I had a blind spot," she conceded in court.

Prosecutors say Gerharstreiter, 48, has changed his identities repeatedly since moving to America 30 years ago. Arriving as an exchange student he adopted several personae, each more complex than the last.

He claimed he was a Rockefeller with a billion dollar art collection but also a relative of Lord Mountbatten and son of Hollywood child star Ann Carter — he once told his wife it would be "beneath a Rockefeller" to get a job.

"He could maintain a lot of different stories for a lot of different people and keep them all straight," Miss Boss said.

Yet the picture Miss Boss painted of her own credulity appears to have stunned even Gerharstreiter's lawyers. For the majority of their 14-year relationship, Miss Boss said she never questioned why he didn't have an income. He variously claimed he worked in third world debt restructuring, a rocket propulsion firm and as a financial trader.

"He was clearly involved in what appeared to be work. He said he went to work but I did not see him there," Miss Boss said. In one story, he said a fall left him mute as a child — until he saw a dog and spontaneously uttered "woofness" at age 10.

He said he couldn't drive — not because he didn't have a licence but because of bad sight. He claimed he couldn't fly because of a bad ear.

He said he'd given his Rockefeller fortune — some $50 million — to the US navy to settle a claim against his father. There was no sign of the art collection, no birth certificate and no family — only a book he claimed was inscribed to him by "Uncle David" Rockefeller.

His one friend from a supposed Harvard education was a woman named Karen Leonard who said: "Isn't it funny we were both there and knew each other but not really."

Gerharstreiter also claimed at one point to have attended Yale aged 14.

It was only after the couple moved from rural New Hampshire in 2007 that Gerharstreiter accepted a divorce settlement of $800,000 in cash, two cars, a ring and a dress he'd bought for Miss Boss. Mother and daughter fled to London where Miss Boss continued consulting with McKinsey.

But when they returned to Boston last July for a supervised visit between Reigh and her father, he snatched her, taking the child to Baltimore where they were found days later by the FBI.

Since his arrest, darker shadows have fallen across Gerharstreiter's past: he has been named as a "person of interest" in the 1985 disappearance of a California couple whose bones were found buried beneath their patio.

Asked why she'd been married to a man for 12 years and still had no idea if he had a bank account, Miss Boss replied: "You're making a connection between business intelligence and personal intelligence. There's a difference. I'm not saying I made a good choice of husband... I'm just saying you can be brilliant and amazing in one area of life and pretty stupid in another."

The case continues.