Goldman's Blankfein to testify alongside trader

Lloyd Blankfein, the chief executive of Goldman Sachs, is considering making a high-risk appearance in front of a US Congressional hearing, alongside the 31-year-old trader at the centre of allegations that Goldman misled clients over toxic mortgage investments before the credit crisis.

The pair are believed to have agreed to testify before the end of this month, to demonstrate that Goldman has nothing to hide over a controversial mortgage deal in 2007 that led to civil fraud charges against the firm last week.

Goldman's partner in the mortgage deal, the hedge fund manager John Paulson, who made $1bn (£650m) from the bet against the US housing market, is also mounting a public fightback. In a letter to his fund's outside investors, made public yesterday, he defended its role in the deal, saying that Paulson & Co had acted transparently and in good faith. Unlike Goldman, Paulson & Co was not charged with any wrongdoing.

Fabrice Tourre was the only Goldman employee also named in the SEC's lawsuit. In an email sent weeks before he sold the mortgage investment vehicle, he wrote: "The whole building is about to collapse... Only potential survivor, the fabulous Fab[rice]... standing in the middle of all these complex, highly leveraged, exotic trades he created without necessarily understanding all of the implications of those monstruosities!!!"

Now based in London, Mr Tourre has been put on paid leave. It was reported yesterday that he had agreed to appear next Tuesday before the House of Representatives committee investigating the credit crisis. Mr Blankfein may appear to answer questions about Goldman's approach to trading mortgage securities before the market collapsed.

Investors, including ABN Amro, lost $1bn when a mortgage investment vehicle called Abacus collapsed in value within months of its creation in 2007. Paulson & Co paid Goldman $15m to set up Abacus and helped put together the portfolio, before betting against it. The SEC says Goldman failed to mention this when it was marketing Abacus, and that Mr Tourre actually misled investors into thinking Paulson & Co had an interest in seeing the vehicle go up in value.

Although there are no charges against Paulson & Co, the allegations are highly sensitive. Mr Paulson's letter indicates a concern that they might withdraw their money, either because they fear lawsuits that will damage the fund, or to avoid the bad publicity. "Paulson did not structure or originate the Abacus transaction" and it was not particularly unusual, he wrote. Goldman constructed 25 similar deals. "All of our dealings were through arms-length transactions with experienced counterparties who had opposing views based on all available information at the time."