A dozen past and present Lehman Brothers executives are reported to have been subpoenaed in connection with three grand jury investigations into the company’s bankruptcy.

The criminal investigations centre on whether the senior Lehman Brothers executives had sought to mislead the markets by making claims about the brokerage’s financial health that they knew to be false.

Harvey Miller, a bankruptcy lawyer with Weil, Gotshal & Manges, which represents Lehman, confirmed that the group was facing three grand jury investigations that have been launched by prosecutors in Brooklyn, Manhattan and Newark, New Jersey.

Lehman Brothers refused to identify the 12 executives who have been issued with subpoenas.

Dick Fuld, the chief executive of Lehman, has consistently denied that he knew the true extent of the brokerage’s problems and insisted that his actions were appropriate on the basis of what he believed to be true.

Lehman Brothers filed for bankruptcy last month as an exodus of customers and billions of dollars of writedowns on investments related to sub-prime mortgages left it on the verge of a meltdown.

Speaking last week at a congressional hearing into the collapse of Lehman Brothers, Mr Fuld said: “No one realised the magnitude of these problems. I said what I believed to be true — that the worst of the impact to the financial markets was behind us. With the benefit of hindsight, I can now say that I, and many others, were wrong.”

Yesterday American media reports named Mr Fuld, Joe Gregory, the former chief operating officer of Lehman, and Erin Callan, the former chief financial officer, as among those who have been subpoenaed, but Lehman declined to confirm or deny the names of those served.

In addition to the subpoenas issued to Lehman executives, it is understood that Ernst & Young, the group’s auditor, BlackRock, a Lehman creditor, and American Insurance Group (AIG), the insurer, have also received subpoenas.

The three grand jury investigations are in addition to an FBI inquiry into whether Lehman Brothers — as well as Fannie Mae, Freddie Mac and AIG — put pressure on ratings agencies to award top ratings to securities they issued. The bureau is concerned that the four groups may have sought to encourage agencies to inflate their ratings by offering higher fees or the promise of more work. That investigation is also understood to be looking at whether senior executives of the four groups intentionally misled investors about the health of their companies.

The latest investigations emerged a day after federal authorities said that they had opened an inquiry into the failure of Washington Mutual, the savings and loans institution that was sold last month to JPMorgan Chase in a fire sale to prevent bankruptcy.

Jeff Sullivan, a US attorney, has joined forces with the FBI, the Federal Deposit Insurance Corporation’s inspector general, the Internal Revenue Service and the Securities and Exchange Commission to look into the collapse of Washington Mutual. Mr Sullivan, who is based in Seattle, said: “Given the significant losses to investors, employees and our community, it is fully appropriate that we scrutinise the activities of the bank, the lenders and others to determine if any federal laws were violated.”

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