A request from bankrupt tycoon Sean Quinn to have two years of phone call recordings examined in preparation for his family's case against the IBRC would take five years to process, lawyers for the bank have claimed.
Responding to an application from the Quinn family to extend the review of the so-called 'Anglo tapes' to capture calls made within the bank as far back as January 2007, McCann Fitzgerald partner Karyn Harty said that a 10-strong team would need to work 10 hours a day to get through the 2.19 million calls she estimated would need to be reviewed.
Ms Harty - who is acknowledged as the country's foremost authority on legal discovery - made the assertion in an affidavit filed two weeks ago on behalf of the Irish Bank Resolution Corporation (IBRC).
Commenting on the Quinn family's request to the High Court to have all phone call recordings held by the former Anglo Irish bank for the period January 1, 2007 to March 31, 2009 reviewed, Ms Harty said that: "Assuming an average call duration of five minutes - and that is not very scientific - it would take a team of 10 reviewers working 10 hours a day a total of five years to complete the audio review of that number of calls."
The cost of the more extensive review now being sought by the Quinns would be "phenomenally high" she said and would, based on her knowledge of the bank personnel involved, see "a very limited possibility of further relevant material emerging".
Ms Harty revealed in her affidavit how the IBRC, which is currently in liquidation, has already incurred a €600,000 bill for the 18,000 phone call recordings her team has reviewed so far.
Elsewhere in the same filing, she confirmed the IBRC spent another €1.55m arising from work carried out by McCann Fitzgerald on discovery for the Quinn case in the period between July and November 2012.
In bringing their civil action against the former Anglo Irish Bank, the Quinn family is denying liability for some €2.34bn of total loans of €2.8bn which they claim were given illegally by the bank to prop up its own share price. The case is due to get under way in the High Court next April.
The bank, meanwhile, is bringing its own case against the Quinns, alleging that members of the family conspired with others to strip assets valued at up to €455m from the Quinns' International Property Group.
The case, which was initiated in June 2011, is currently stayed on foot of a request from the Director of Public Prosecutions.
Explaining the process her team follows in reviewing phone call recordings from the bank, Ms Harty said: "The only way to identify relevant calls is to select an extension, request a copy of the audio calls for that extension over a defined period and listen to the calls in real time.
"That is a very time-consuming process. It is extremely labour intensive and the process of retrieving the data is difficult from a technical perspective and very expensive."
Ms Harty added that she was "not aware of any commercially available technology that would allow for the searching of audio files for 'relevant files without the need for 'real time' reviewing by individual reviewers".
She asked if it was "proportionate" to require the IBRC to conduct a full review of calls from the phone lines of the many individuals within the bank who were not directly involved in the matters which form the subject of the Quinn proceedings.
But while the IBRC's lawyers maintain it would not be "feasible" to review the estimated 2.19 million phone call recordings the Quinn family's request could entail, there are software packages available which allow for the accelerated processing and indexing of audio files.
In the case of Symantec's Clearwell eDiscovery Platform package for instance, up to 20,000 hours of recorded audio can be indexed per day once the user provides the system with the specific phonetic terms they are looking for.
The Symantec package has already been recommended to companies in the United States looking to meet the increased regulatory requirements set down by the Dodd Frank Wall Street Reform and Consumer Protection Act.
Asked by the Sunday Independent if McCann Fitzgerald had considered Symantec's software for discovery in the Quinn case, a spokesman for the firm declined to comment on the basis that the matter was due before the High Court next month.