Former solicitor Thomas Byrne has told the Circuit Criminal Court he never meant to defraud anyone.
The 47-year-old from Walkinstown Road in Crumlin has pleaded not guilty to 50 theft and fraud offences totalling almost €52m.
The charges allege he transferred clients' homes into his name and used them as security for loans and that he forged documents between 2004 and 2007.
Mr Byrne took the witness stand in his own defence.
He said he had a very busy solicitors' practice in Walkinstown, but a property developer called John Kelly became his biggest client.
He said from the year 2000 onwards, there was such a demand on his client account from Mr Kelly that he was always in difficulty.
The Law Society had sent in accountants to monitor his practice, he said.
From 2002 to 2007, he said, things became very difficult for him.
He said Mr Kelly, who had been started off as his business partner in a property deal, inveigled himself into the office and became very aggressive.
He said Mr Kelly had told him he had a brother involved with people up the North and was quite aggressive in his demands for money.
He said Mr Kelly had a voracious appetite for money but had no income and he was financing his day-to-day lifestyle.
By 2007, he said Mr Kelly was demanding finance of €450,000 a week.
Mr Byrne, who broke down at several points during his evidence, said he could not cope and started drinking heavily and taking tablets.
He said he felt Mr Kelly was threatening his family.
Mr Byrne said he never intended to defraud anyone.
He said he did not want an outlandish lifestyle and was happy with his small little busy practice.
Mr Byrne said the one thing the State had not said was where any of the money went - because he did not have any of it and never did have any of it.
He said everyone could see there was something untoward going on in the practice.
Mr Byrne said when a complaint was made to the Law Society, Mr Kelly told him to leave the country.
He broke down as he described travelling to Holyhead then on to London and Brighton.
Mr Byrne said that when his colleague Barbara Cooney made a complaint to the law society in October 2007, Mr Kelly phoned him and told him to leave the country. He said he was told there would be serious consequences if he did not.
He was terrified of him and terrified about his family's welfare, he added
Mr Byrne said he was told to go to a centra shop in Rathmines. He said he was brought to a walk in freezer at the back of the shop.
He said he thought he was going to be killed. He was given €10,000 in used sterling and euro notes.
He then headed to Holyhead, London and Brighton before being persuaded to return to Ireland.
He said he was not saying he was entirely innocent. "Of course I'm not" he said.
He said he was in court to face the music and was terrified about what was going to happen, but he said it was preferable to being bullied by Mr Kelly.
Mr Byrne said he was very sorry that there were people who got caught in the crossfire and were not paid because his practice closed.