The judge presiding over the Commercial Division of the High Court has expressed surprise that only 11 gardaí are involved in the investigation by the Director of Corporate Enforcement into the former Anglo Irish Bank.

Mr Justice Peter Kelly said the small number of gardaí involved in what is the most serious investigation of this type in the history of the State was extraordinary.

The judge was told by lawyers for the Director that 19 people in total were involved in the investigation - 11 gardaí and eight members of the director's staff.

Senior Counsel Paul O'Higgins said the Director was satisfied with the number of staff he had.

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

Mr Justice Kelly was hearing an application by the Director of Corporate Enforcement for a further extension of time to hold and examine certain electronic data seized from the bank in September 2009.

The judge granted a further extension of six months for the investigation.

But he said that notwithstanding the complexity of the investigation, the huge amount of documentation to be examined and witnesses to be interviewed, the investigation seemed to be taking a very long time.

He said that refusing to grant the order, however, would mean that the documents seized could not be relied on in any possible future criminal prosecution.

Mr Justice Kelly said he was glad to hear that a decision which had been taken by the office of the Director of Public Prosecutions that no one would be prosecuted until all five strands of the investigation were completed, was being reviewed.

Some strands were nearer completion than others, the court heard.

Úna Ní Raifeartaigh, Senior Counsel for the DPP, said that decision was being looked at again.

She said it may be possible that isolated decisions in relation to one or two of the strands could be taken and decisions to charge people could be taken in the next month or two.