Gardai are unable to examine more than 100 key files in their investigation into Anglo Irish Bank because former senior executives have not handed over the computer passwords.
Former Anglo staff hold passwords to about 200 documents vital to the inquiries being carried out jointly by the Garda Fraud Bureau and the Director of Corporate Enforcement.
The passwords for around a third of the encrypted documents have been produced so far by the bank. But Anglo admitted it has been unable up to now to secure the rest.
Among the former employees being contacted by Anglo to establish if they have knowledge of the missing passwords is its ex-chairman Sean FitzPatrick.
Gardai are using state-of-the-art technology to crack the password puzzle and are confident they will be able to gain access to all of the key documents.
But they indicated yesterday that the absence of the passwords was one of the factors which have delayed the completion of their inquiries.
It also emerged that one of the main areas of investigation was the provision of loans to an Anglo director to establish if the move was contrary to criminal law or the Companies Act.
The disclosures came as a Commercial Court judge yesterday granted an application by corporate enforcement officials to extend the Anglo investigation for a further six months.
Mr Justice Peter Kelly said he expected that the Director of Public Prosecutions (DPP) should be able to decide earlier than normal in a complex investigation on whether criminal charges were warranted.
In this case the DPP already had a lot of information through the day-to-day involvement of his lawyers in the inquiries.
Some files will be sent to the DPP before the end of the year, while others will be forwarded in the first quarter of 2011, Garda Supt Eamonn Keogh, who was seconded from the fraud bureau to the corporate enforcement office, told the court in an affidavit.
Mr Justice Kelly said while it was regrettable the inquiry was taking so long, this had to be balanced against the complexity of the investigation, the volume of material involved and the difficulty trying to open electronically stored material without passwords.
In the circumstances, he said, he would grant the application by corporate enforcement director Paul Appleby to extend the investigation for a further six months, when he hoped the court would then be told it had been completed.
Three of the five issues under investigation should be completed by the end of December and the others in March.
The court was told that four key areas of inquiry centred on:
In connection with the purchase of shares, some 125 witness statements have been taken. Further statements are being prepared.
Gardai are also using mutual assistance arrangements with the UK to obtain witness statements from staff of the international firm Morgan Stanley in a London court. This will be resumed in the middle of the month when a senior counsel involved in the inquiry here will travel to London to cross-examine the witnesses.
In relation to the loans to directors, some 65 witness statements have been taken.
The fraud bureau is taking the lead role in inquiries into the "back-to-back" deposit deal and this investigation should be completed within the next seven weeks.
The probe into loans to a director has also progressed substantially.
The fifth issue centres on whether the other four involve breaches of EU regulations.