Fraudster businessman Breifne O’Brien has been jailed for seven years for running a Ponzi scheme which costs his victims millions.

O'Brien used the stolen cash to pay for an extension to his house, a new car for his wife and the stamp duty on new properties, in the multi-million euro scheme.

He convinced long-standing friends from his days in Trinity College Dublin and family business associates that he was linked to property deals in Paris, Manchester and Hamburg and a shipping insurance scheme.

The deals were all bogus. O'Brien used fake letters and invented connections to international businessmen and lawyers to get the victims to continue to give him money.

O'Brien (aged 52), of Kilmore, Monkstown Grove, County Dublin, pleaded guilty at Dublin Circuit Criminal Court to 14 sample counts out of a total of 45 theft and deception charges at National Irish Bank and Ulster Bank, Donnybrook, Dublin on dates between 2003 and 2008.

O'Brien, whose family home is Carrigrohane Castle, Co Cork, had denied all charges, but changed his plea to guilty on the day his trial was due to start.

The court heard that the total loss to the five victims is €8.5m and that O'Brien owes further amounts to other creditors.

Shane Costello SC, prosecuting, said that so far €420,000 has been recovered through the release of assets owned by O'Brien but that none of this is available to the victims. At a previous hearing it was incorrectly stated that the amount recovered was €2m.

Counsel for O'Brien said that he has already transferred his entitlement to GBP£1,065,000 worth of shares in a UK computer gaming company to the creditors group but that these shares have not yet been realised.

He has also signed documents in relation to other loan notes and investments and has been in early discussions with a group of investors with regard to other foreign properties.

Mr Costello said that even if every euro set out in a “highly speculative” schedule of assets presented by O'Brien's counsel was realised it would have to be divided up between the victims in this case and a larger group of creditors.

Judge Patricia Ryan said the central lie in the case was that the money given to O'Brien was not retained in his deposit account but instead used for a myriad of purposes.

Lawyers for the fraudster said that he is now destitute and is living on social welfare of €188 a week.

Patrick McGrath SC, defending, said O’Brien was previously described as the “poster boy for the worst excesses of the Celtic Tiger”, “Ireland’s Bernie Madoff” and a “high society con man” is now shunned and socially ruined.

O'Brien told investors that the money would be left sitting in a deposit account in order to demonstrate that he had the financial clout to purchase investment properties and allow him to procure exclusive options on the properties. He told them he would flip these deals on for profit and split the proceeds with the investor.

Detective Sergeant Martin Griffin told the court that this was all a lie. The money was used for a myriad of other purposes instead of being held on deposit, he said.

Some of it would be used to pay back other investors who had advanced money to O'Brien, a process the detective described as “grooming”.

He said: “This is absolutely quintessentially characteristic of a Ponzi scheme”.

Det Sgt Griffin said that the fraud followed a pattern of telling investors: “Give me money. I will retain it in my deposit account. It will not go anywhere else other than to show I have access to the money”.

The first victim was Tipperary farmer Louis Dowley who was conned out of a total of €6.95m. O’Brien knew Dowley because his wife had attended Trinity College along with O’Brien in the early 1980s.

In 2004, he told Dowley that if he put money up to show as a deposit for a property investment scheme in Manchester, O’Brien would share the return with him.

He also drew Dowley into an insurance shipping scheme which he said would save on insurance for shipments of linen.

In order to advance this con he faked an email from an Italian shipping merchant who he had met briefly during a New Years Eve party in Dubai when they exchanged business cards. He also faked an email from a Monaco-based lawyer.

In July 2006 Mr Dowley lodged one million euro into a bank account for this linen shipping venture. Within two days O’Brien had transferred €19,000 to one of his companies, used €874,134 for stamp duty on a property in Cork city, €219,024 for purchase of another property and €61,000 for the purchase of an Audi Q7 car for his wife.

Det Sgt Griffin said: “Very quickly within two days the million euro is as good as gone”.

The other victims named in the charges are Martin O'Brien of Naas, Co Kildare, Dubliners Pat Doyle and Evan Newall, and Daniel Maher of Foxrock, Co Dublin.

O'Brien stole €4m from Mr Dowley, of Carrick-on-Suir. He deceived Mr Doyle and Mr O’Brien of €500,000; Mr Newall of a total of about €3m; and Mr Maher of €450,000. The deception against Mr Newell relates to the sale of lands in Dunshaughlin, Co Meath.

Det Sgt Griffin told the court that O'Brien knew some of the victims from his days studying economics in Trinity College Dublin. He had known many of them for over two decades and O'Brien and the victims would have attended wedding, christenings and ski holidays together over the years.

Counsel for O’Brien said his fall from grace as a high living socialite was met by a media blitz which emphasised the opulence and wealth of his former lifestyle and referred to him and his wife as the golden couple.

He said: “All the accoutrements to the lavish lifestyle are well gone. Not only has he lost the lifestyle, but he has effectively lost his family”.