The 210-page presentation, showing a snapshot of outstanding corporate loans of more than €45m (£38m) as of September 25, has been posted on the Wikileaks website.
Many of the largest exposures are to British-based businesses and entrepreneurs including property investors Robert and Vincent Tchenguiz, their former brother-in-law Vivian Imerman, Simon Halabi, Nick and Christian Candy, Peter Shalson and Aneel Mussarat.
The leaked document also reveals the extent to which Kaupthing had been lending to those with a major economic interest in the bank's shares. For example it sets out a complex web of loans and shares posted as collateral between the bank, holding company Exista, which owned 23% of Kaupthing, and Exista's controlling shareholders Agust and Lydur Gudmundsson.
Total Kaupthing loans to Exita and its subsidiaries reached €1.43bn, with considerable sums extended without security or covenants.
Robert Tchenguiz, the second largest borrower from Kaupthing, with loans of €1.37bn, is also among those who had an interest in Kaupthing shares, as he was a major shareholder in Exista. Meanwhile veteran British retailer, Kevin Stanford, was said to rank as the fourth largest investor in Kaupthing, with 30.9m shares. Kaupthing loans to him and his companies totalled €519m, according to the leaked document.
While there is no suggestion of wrongdoing, several Icelandic authorities and Kaupthing's resolution committee are examining the complex and multi- faceted relationship between the bank and some of its largest customers prior to its collapse. They are looking to rule out conflicts of interest.
The leaked document provides a snapshot of Kaupthing's loans at a critical moment before the bank's demise. Many of the borrowing arrangements shown will since have been refinanced or revalued.
Kaupthing's resolution committee has sought to have the presentation removed from the internet and has secured a temporary injunction against its publication by certain Icelandic media. A source at the bank insisted it was keen to see all questions about its collapse answered, but it was still bound by a duty of confidentiality to customers.
Alongside each loan, the leaked presentation provides a brief assessment of the risk tied to the loans and, on occasion, the state of relations with the customer. "Asset rich and frequently cash poor, limiting his ability to meet margin calls", reads one summary. Another states: "Relationship ... has become strained as downturn has impacted their business model. They build for the uber-rich but sales are slowing".
A third loan risk summary states: "There is a glut of apartments in Manchester and it is questionable whether construction should be commenced. It is probable that an updated valuation would lead to a breach of covenant."
In March Kaarlo Jännäri, former head of the Finnish financial regulator, published a damning independent analysis of the Icelandic banking system and its collapse. Commissioned by the Icelandic government and International Monetary Fund, the report highlighted a series of concerns about the conduct of the banks, including large exposures to individual clients and business conducted with related parties, such as those with an interest in bank shares.
Jännäri noted that at the end of June 2008, Iceland's big three banks – Kaupthing, Glitnir and Landsbanki – had a total of 23 loan exposures to individuals or corporate groups that were equivalent to more than 10% of the respective bank's funds."What is striking about these exposures is that the majority of them are to holding companies, or other institutions, or individuals whose main activity is investing in shares or other venture-capital or speculative activities," he said.
"In most cases, the assets pledged as collateral for these loans are shares in the companies in which these customers had invested the funds borrowed... My judgment is that their behaviour in this regard has been very imprudent."