With his famous name, ostentatious display of wealth and upper-class accent, Clark Rockefeller was a pillar of respectability in the smart society of the American East Coast.

Yet police hunting Mr Rockefeller for abducting his daughter, who lives in London with her mother, admitted yesterday that they could find no trace of his existence before the early 1990s.

Detectives described Mr Rockefeller, 48, as a “ghost” who appears to have laid a false trail of clues as he planned the abduction of his daughter, Reigh Boss, 7, on Sunday.

His former wife of 12 years, Sandra Boss, 41, moved to London with Reigh this year. The wealthy socialite is a senior partner with McKinsey & Co, a management consulting firm.

She had taken Reigh back to Boston, Massachusetts, for an access visit supervised by a private social worker. Mr Rockefeller grabbed his daughter, known as Snooks, and bundled her into a waiting car.

Detectives are searching for any documentation, such as a social security number or birth certificate, that would give them an idea about who Mr Rockefeller really is. The oldest record traced is from the early 1990s, when he was listed as living on East 59th Street in Manhattan.

A high-ranking Boston police official told ABC News: “Nobody knows who this guy is. He is a ghost.”

The FBI last night revealed that Mr Rockefeller possesses a passport in the name Michael Brown.

They also said that Reigh’s blonde hair could have been cut short so she resembles a boy.

In a formal “wanted” appeal the FBI said Mr Rockefeller uses the aliases J.P. Clark Rockefeller, James Frederick, Clark M. Rockefeller III, Clark Mill Rockefeller, Clark Rockerfeller and Michael Brown.

Police also confirmed that his bank records show a recent withdrawal of a large amount of cash to buy gold coins, which would be impossible to trace and easy to convert back into cash abroad.

Mr Rockefeller is known to have used several aliases and to have suggested to friends that he was working for the Pentagon, either as a mathematician or physicist. He met Ms Boss, a graduate of Stanford and Harvard Business School, in the early 1990s when she worked on Wall Street for Merrill Lynch. They are believed to have married in 1995, but a certificate cannot be traced.

Friends said that although he never explicitly claimed to be part of the oil dynasty, he did not deny being a member of the family.

Some friends recalled him saying that his parents had died in a car crash when he was a child, others that he was schooled at home before attending Yale, which has no record of him. He also talked passionately about South Africa, leading some to assume that he had lived there.

After Reigh’s birth he was her main carer while his wife worked. As well as her financial career, she was also an aide to Michael Bloomberg, the Mayor of New York. Friends said that Mr Rockefeller was devastated at losing custody of Reigh — a ruling based partly on his wife’s concerns about his past.

After snatching Reigh he was driven to New York by a friend, Aileen Ang, who was paid $500 to pick them up at a Boston store where he had bought two dresses.

Ms Ang said she thought that Mr Rockefeller had custody of Reigh and described how she played happily in the back of the car. “She was actually saying — I can’t quote exactly — but was kind of like, ‘I love you too much, Daddy’. And he would respond, ‘I love you even more’,” Ms Ang said.

During the journey Mr Rockefeller talked about a 72ft yacht called Serenity that he planned to use to flee the country, suggesting that he would sail to Bermuda or Peru. His daughter seemed excited by the prospect.

Ms Ang said: “Nobody knew for sure what he was actually going to do, because he could have been just feeding me lines.”

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