In the week before the Government's bank guarantee scheme, there was a run on Anglo Irish Bank with €5.4 billion in corporate and retail deposits withdrawn.
A consultants' report, published tonight, found that Anglo Irish Bank lost the deposits in a single week last September, just days before the Government issued its guarantee covering six Irish banks.
The PriceWaterhouseCoopers (PwC) report said: "As of September 27th, Anglo was forecasting net negative cash of €12.0 billion by October 17th."
The report, which was compiled on behalf of the Government, also found it had 15 banking relationships in excess of €500 million. It concluded that the size of the exposures signifcantly increased the bank's risk profile.
Minister for Finance Brian Lenihan tonight said the report "demonstrated that the Government was right to nationalise the bank earlier this year."
The summary report contains extracts from three reports on Anglo Irish Bank prepared by the consultants for the Financial Regulator.
The vast bulk of the report is a description of customers' loan exposures, none of which is included in the summary report, published this evening.
"Anglo's business model was successful with many years of uninterrupted profit growth, however, in common with the sector, changing economic circumstances highlight a number of key underlying risks," it said.
"The Bank's profitability has developed strongly over the last eight years, driven by lending advances growth and a low cost to income ratio "approximately one quarter of the loan book at 30th September 2008 was development based," it added.
The report noted that the bank has exposures to a number of customers who also have significant exposures to other domestic and foreign banks.
"There is a risk that (i) if other banks call in their loans customers may not have the resources to pay these and Anglo's loans or (ii) these other banks may not participate in new rounds of refinancing," it said.
It continues: "A number of key property developer customers purchase or take options over land banks a considerable period of time in advance of local area plans, zoning, planning permission etc. being available. As a result they may end up carrying land at a low base cost relative to current market values.
"In recent years this model would have allowed them to accrue significant uplifts in value over time which they realise by selling sites with planning permission or through development. The risk is whether with their equity and other resources they have the ability to carry the interest due on loans funding the transactions."
In a statement released to coincide with the publication of the report, Minister for Finance Brian Lenihan said it contained "as much information as possible given the legal constraints and the need to maintain client bank confidentiality, which is essential to maintain depositor confidence in the bank."
"The report clearly demonstrates the Government was correct to guarantee the financial system last September at a time when financial market liquidity conditions were under severe pressure, said Mr Lenihan.
"The report deals with certain loan loss scenarios. These are not predictions but rather were intended to show how the bank's loan book would perform under various stress conditions," he added.
However, Fine Gael criticised the delay in publishing the report.
"The significant delay by the Government in releasing the heavily-edited PricewaterhouseCoopers report on Anglo Irish Bank, and its secretive approach throughout, do nothing to inspire confidence in the Government's handling of this crisis," said Fine Gael deputy leader & Finance spokesman Richard Bruton.
"However, this is typical of the inept manner in which the Government has dealt this matter and the widespread concerns of taxpayers. The investigation into Anglo Irish must be passed on to the Office of the Director of Corporate Enforcement as soon as possible."