Businessman Breifne O'Brien used money advanced to him by friends and acquaintances for investment in property and businesses to buy properties for himself, extend his house and buy a car for his wife, the Dublin Circuit Criminal Court has been told.
O'Brien also used money given to him for investment to pay back others, something which was "absolutely quintessentially characteristic of a Ponzi scheme" the court heard.
O'Brien, who is 52 and lives in Monkstown in Co Dublin, has pleaded guilty to 14 sample counts of deception and theft involving sums totalling around €11 million between 2003 and 2008.
He dishonestly induced five people to advance millions of euro to him to invest in bogus property deals in Manchester, Paris and Hamburg.
He also got them to invest money in a bogus linen shipping insurance scheme.
The court heard evidence before sentencing the businessman.
Detective Sergeant Martin Griffin, who was in charge of the garda investigation into the crimes, said the investigation had begun after Commercial Court judge, Mr Justice Peter Kelly referred the matter to the fraud squad in 2008.
Prosecuting counsel Luán Ó Braonáin outlined how the five men O'Brien had deceived were old friends or people who had been introduced to him by family friends.
One of the victims, Louis Dowley, knew O'Brien for 25 years as his wife had been in Trinity College with him.
The court heard O'Brien had 83 different bank accounts with six different financial institutions, although only eight bank accounts featured in the charges before the court.
The court heard he had been involved in a laundry and taxi cab business. His father was involved in business in Cork and his sister's husband was a very successful businessman.
Det Sgt Griffin agreed that the way O'Brien operated was to ask people for money in relation to an alleged investment.
He would assure them that he would retain the money in his deposit account and use it to allow him to get an option on a deal.
However the money was not kept in his deposit account. It was used to pay others in a manner described by Mr Ó Braonáin as being absolutely characteristic of a Ponzi scheme.
It was also used to pay stamp duty on properties, an extension to his home and an Audi Q7 car for his wife as well as other transactions the court heard.
Det Sgt Griffin agreed that €1m given to O'Brien in July 2006 by Mr Dowley, for an investment allegedly relating to a linen shipping insurance scheme, was dissipated within two days.
He told the court that within two days the €1m was as good as gone.
O'Brien used €61,000 of this money to buy an Audi Q7 car for his wife.
O'Brien is now destitute and lives on €188 a week, the Dublin Circuit Criminal Court heard.
He was eventually confronted by two brothers who lost more than €3m and attended a meeting in a Dublin solicitor's office with some of his creditors, where he admitted everything.
The solicitor, Brian Quigley, said O'Brien expressed sorrow and remorse at this meeting, but also said it was "easy to pull the suckers in while the economy was booming".
O'Brien denies saying that.
The court heard O'Brien's crimes have had a devastating financial effect on the injured parties.
One of them, Pat Doyle, who lost €500,000, said that he was not able to give his children the kind of education he had planned to give them, although O'Brien had been able to give such an education to his children.
His lawyer told the court O'Brien had lost his home, his marriage had ended and he had lost meaningful contact with his three children.
He had lost contact with his elderly father who had guaranteed some of his transactions, unaware his son had no funds to meet them.
He said the accoutrements to the lavish lifestyle he had once had were well gone.
He was now living an entirely different life to the life he had in 2008.
He had been portrayed in the media as the poster boy for the worst excesses of the Celtic Tiger.
The court was told O'Brien always believed the people who had given him money would get their money back.
His defence counsel Patrick McGrath said O'Brien showed genuine remorse and was doing everything he could to make good the losses to the injured parties to the extent he could.
The court was told the crimes had had a devastating financial effect on the injured parties.
The injured parties have also claimed, the court heard, that O'Brien has not signed documents he needs to sign to ensure that assets that are available can be sold to repay some of the money.
O'Brien, the court heard, is willing to sign anything he needs to release assets.
The court also heard that the losses to the injured parties in this case total €8.5m.
So far, €2m has been recovered, but none of this has gone to the injured parties.
Asked why not, prosecuting counsel Mr Ó Braonáin said there had been "huge legal costs".
Judge Patricia Ryan wants clarification on what assets have been realised and repaid to injured parties and O'Brien will be sentenced on 8 October.