In his evidence to the trial, the lead investigator from the Office of the Director of Corporate Enforcement, Kevin O'Connell, acknowledged that during the investigation, he had given assurances to Government on behalf of the ODCE that they didn't need further resources.

He said in hindsight this was wrong. There were too few people trying to do too much, he said.

He said his garda colleagues were working "flat out" on the other investigation being carried out by the ODCE - into the alleged provision of illegal loans by Anglo to buy shares in the bank.

He agreed he had expected this investigation to take "centre stage" eventually but that did not happen.

In January 2012, Mr Justice Peter Kelly, who was then presiding over the commercial division of the High Court, expressed surprise that only 11 gardaí were involved in the investigations by the Director of Corporate Enforcement.

He said the small number of gardaí involved in what was the most serious investigation of this type in the history of the State was extraordinary.

He was told by lawyers for the ODCE at that time that 19 people in total were involved in the investigation and he was told by Senior Counsel Paul O'Higgins that the Director was satisfied with the number of staff he had.

Mr O'Higgins told the court it was highly specialised work and assigning more gardaí to the investigation would not necessarily speed it up and a lack of gardaí had not led to delays in completing the investigation.

The court had to hear a number of applications from the ODCE in relation to retaining electronic data seized from Anglo.

The judge repeatedly criticised the length of time the investigations were taking.

In his evidence to the trial of Mr FitzPatrick, Kevin O'Connell was also keen to emphasise that other people knew how the investigation was being conducted.

The Minister for Enterprise, Trade and Innovation, who is responsible for the ODCE, received a report in March 2011 outlining the progress of the investigation and noting that the extent to which witnesses required the assistance of legal advisers was unusual and uncommon in the experience of the gardaí.

There was also a preliminary report for the DPP in December 2010, which Mr O'Connell agreed showed the DPP's office was aware of the manner in which statements were taken to some extent.

And Mr O'Connell was asked about a "crucial email" sent by him to the DPP's office in 2012, which outlined how a supplementary statement from one of the EY's auditors, Vincent Bergin was being prepared.

Mr O'Connell said he felt this email "touched very considerably" on the question of who knew what about how the statements were being taken by the ODCE and how he had been operating in the way he was for so long.

Mr O'Connell agreed he felt he was going to be hung out to dry when he was told in 2015 that this email was not being disclosed to the defence. It was later disclosed.