A High Court judge has expressed serious concern about delays in completing the investigation by the Director of Corporate Enforcement and Garda into Anglo Irish Bank.

The investigation is not expected to be completed until the end of this year.

The ODCE investigation, assisted by the Garda Bureau of Fraud Investigation, began almost two and a half years ago after millions of files were seized from the bank in February 2009.

Mr Justice Peter Kelly was told today "every effort" would be made to complete it by the end of this year and was asked to make orders effectively extending the investigation for another six months. He has reserved his decision to Tuesday next.

Files and reports running to 12,000 pages and related to three of the five issues being investigated were sent to the DPP in December 2010 and March last but the judge was told there was no information whether any decision had been made on those files.

On completion of the ODCE investigation, one of several into Anglo, it could take another two years to complete any criminal prosecution.

Mr Justice Kelly had asked to be updated today on the progress of the investigation. At one stage, he asked was the investigation "ever going to come to an end?"

He noted it had been adjourned and extended six times by the court and remarked he was not "a rubber stamp".

The judge noted he was previously told the investigation was expected to substantially complete by the end of last year but was now being told differently. He stressed he appreciated the matters being investigated were complex but reiterated his concern at the delay in investigating such serious matters.

Paul O'Higgins SC, for the ODCE, said his client was doing all it could but this was a very complex inquiry involving millions of documents and certain matters were outside his control.

Some former Anglo personnel had refused to attend for interview or provide witness statements, one person took nine months to provide a witness statement and the Director could not compel persons to attend for interviews.

The current Anglo team was co-operating with the investigation and claims of privilege by the bank were confined to a small number of documents, it was stated.

Counsel also said he could not answer some of the judge's queries in light of any possible criminal proceedings.

Four issues are being investigated to establish if they involve possible breaches of the Companies Acts and/or common law.

The first is the financial assistance by Anglo in 2008 to a number of persons to enable them buy its shares.

The second is Anglo's loans to its former directors and the regular "warehousing " in Irish Nationwide Building Society of some of those loans at the end of Anglo's financial year.

The third issue is the 'back-to-back' deposit arrangement between Anglo and Irish Life and Permanent Group for the benefit of Anglo at the end of its financial year in September 2008. The fourth relates to a loan to an Anglo director.

The fifth issue is whether the other four involve breaches of the EC Transparency Regulations and the European Communities (Admission to Listing and Miscellaneous Provisions) Regulations 2007 and cannot complete until the investigations into the other four issues conclude.

In an affidavit, Supt Eamonn Keogh said the investigation into the first issue was about 90 per cent complete and an 8,000-page file related to that was sent to the DPP last March. Some important interviews had yet to be concluded and when that was done, additional evidence would be given to the DPP. The GBFI also last December gave the DPP a file relating to market abuse matters relevant to issue one, he said.

A small amount of work had still to be done on issue one, including obtaining documents, required under the Bankers' Books Evidence Acts, and under mutual assistance procedures in the UK, he added.

A report on the second issue was sent to the DPP last December and more documents were required under the Bankers' Acts, he said. About 50 witnesses still had to be interviewed on this matter and "every effort" was being made to complete investigation of that by the end of this year.

Supt Keogh said files on the third and fourth issues were sent to the DPP in December last. The investigation into the fifth issue, as it related to interconnected events, had to await the outcome of the investigations into the other four issues.

The ODCE, Garda Commissioner and their staff were co-operating closely in the investigations, he said. Last year, 280 witness statements were taken, many requiring extensive advance preparation, he added.