Last year’s stock market slump was the nail in the coffin for the company run by Sunqvist, who was ranked among Sweden’s richest individuals in 2007.

For several years, Sundqvist had financed large share purchases in publicly traded companies, but amid steep stock market loses in 2008, he was forced to divest much of his portfolio, including stakes in toolmaker Hexagon and the Öresund investment company.

In the autumn, Sweden’s National Debt Office (Riksgälden) lent Carnegie several million kronor to help cover the bank’s loans to Sundqvist.

When the Financial Supervisory Authority (Finansinspektionen) revoked Carnegie’s licence in November, the Debt Office took over the investment bank, which stands to lose around one billion kronor from loans it made to Sundqvist.

But now it appears as if Sundqvist’s fraudulent stock deals may also end up costing Handelsbanken 900 million kronor, according to a report by the Dagens Industri (DI) newspaper.

Sundqvist’s company, Landå, borrowed 1.7 billion kronor from Handelsbanken in 2007 in order to finance the purchase of stock in the Industrivärlden investment firm.

Those shares are now worth only 700 million kronor.

Handelsbanken refused to comment on the report.

According to DI, the loan for the shares is secured by stock in Sundqvist’s private real estate company. But several other banks, including Carnegie, also have interests in the same company, meaning that Handelsbanken’s ultimate loss depends on the outcome of negotiations with other banks looking to minimize their exposure on deals with Sundqvist.

A well-know real estate investor from Jämtland in northwestern Sweden, Sundqvist had a stock portfolio valued at more than 12 billion kronor in 2007.

According to Sundqvist, his real estate holdings, made up primarily of commercial office properties, store fronts, and a few warehouses, are worth between 7 and 8 billion kronor.

His assets come from the sale of a bus company founded by his father. Following the sale, all of Sundqvist’s corporate activities were placed within one holding company, Skrindan.

In Jämtland, Sundqvist is something of a celebrity for his grandiose plans to invest a billion kronor in the ambitious Björntanden project near Östersund.

Plans included building an arena with capacity for 3,000 people and a 250-room hotel and conference centre designed by world-renowned Swedish architect Gert Wingårdh.

The facility was to be built on Frös island and connected to central Östersund by a gondola, and Sundqvist was set to be one of the project’s main sponsors.

But Sundqvist’s financial troubles have put Björntanden on ice, much to the dismay of local officials in Östersund, who hoped the facility would provide a much needed boost to a local economy still struggling to recover from the closure of a military base in 2004.