McClatchy has obtained previously undisclosed documents that provide a closer look at the shadowy $1.3 trillion market since 2002 for complex offshore deals, which Chicago financial consultant and frequent Goldman critic Janet Tavakoli said at times met "every definition of a Ponzi scheme."

The documents include the offering circulars for 40 of Goldman's estimated 148 deals in the Cayman Islands over a seven-year period, including a dozen of its more exotic transactions tied to mortgages and consumer loans that it marketed in 2006 and 2007, at the crest of the booming market for subprime mortgages to marginally qualified borrowers.

In some of these transactions, investors not only bought shaky securities backed by residential mortgages, but also took on the role of insurers by agreeing to pay Goldman and others massive sums if risky home loans nose-dived in value - as Goldman was effectively betting they would.

Some of the investors, including foreign banks and even Wall Street giant Merrill Lynch, may have been comforted by the high grades Wall Street ratings agencies had assigned to many of the securities. However, some of the buyers apparently agreed to insure Goldman well after the performance of many offshore deals weakened significantly beginning in June 2006.

Goldman said those investors were fully informed of the risks they were taking.