A wealthy socialite has made an emotional appeal for the return of her daughter as police started to unravel the mysterious past of her former husband.

Sandra Boss, a London-based financier, pleaded with former husband, Clark Rockefeller, to return their daughter who he had abducted during an access visit in Boston, Massachusetts, last Sunday.

Police hunting for Reigh Boss, 7, who is known as Snooks, said they believe Mr Clark, 48, is using a passport with the name Michael Brown and may be attempting to pass of his daughter as a boy.

Ms Boss, 41, has recorded an extraordinary appeal to her former husband in which she tells him they can still solve their differences.

Staring directly at the camera, Miss Boss says: “Clark, Although many things have changed, you will always be Reigh’s father and I will always be Reigh’s mother.

“We both love her dearly and have only her best interests and well-being in our hearts. I ask you now, please please bring ‘Snooks’ back. There has to be a better way for us to solve our differences than this way.

“I also want to thank everyone for your help.

“And Reigh, honey, I love you and miss you so much. Remember you’re always a princess.”

The couple are believed to have married in 1995 and their divorce was finalised last December. Ms Boss won custody and moved to London where she is a senior partner for with McKinsey & Co, a management consulting firm.

The New York Post today reports unsubstantiated claims that Mr Rockefeller accepted a “significant” amount on money from his former wife to give up custody of their daughter without a fight.

Detectives described Mr Rockefeller as a “ghost” who appears to have laid a false trail of clues as he planned the abduction of his daughter. Police have admitted that they can find no trace of his existence before the early 1990s.

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 said it believes 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 had 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.

Times Recommends

• 'New York has lost its edge'
• Copenhagen will fail – and quite right too
• More than 17,000 new underwater species found