LOS ANGELES (MarketWatch) -- Bankrupt financial giant Lehman Bros.' former top officers, its auditor and several rival brokers could face legal claims, a court-appointed examiner said in a report released Thursday.

In a 2,200-page report, examiner Anton Valukas said that while Lehman's directors at the time of the collapse weren't necessarily responsible, some of its top executive management might be held liable, according to reports of the findings.

Lehman is currently undergoing court-supervised liquidation to pay off creditors.

Valukas mentioned ex-Chief Executive Dick Fuld and chief financial officers Chris O'Meara, Erin Callan and Ian Lowitt as possibly facing claims for negligence or breach of duty.

The report cited a practice known internally as "Repo 105," in which Lehman allegedly used repurchase agreements -- the temporary exchange of assets for cash -- that were structured as sales so that the leverage could be moved off the firm's balance sheet. See story on Lehman's accounting "drug" Repo 105.

As a result, the report says, Lehman may have already been insolvent on Sept. 2, 2008, almost two weeks before its Sept. 15 bankruptcy filing rocked the financial world and helped send the stock market into a nosedive.

"In this way, unbeknownst to the investing public, rating agencies, government regulators, and Lehman's board of directors, Lehman reverse engineered the firm's net leverage ratio for public consumption," the report said.

A Reuters report quoted an attorney representing Fuld as saying the former CEO "did not know what those transactions were" and that "he didn't structure them or negotiate them, nor was he aware of their accounting treatment."

The Valukas report also said evidence exists to support a professional malpractice claim against Lehman auditor Ernst & Young, as the firm "took no steps to question or challenge the non-disclosure by Lehman of its use of $50 billion of temporary, off-balance sheet transactions," according to the Journal.

"Lehman's bankruptcy, which occurred in September 2008, was the result of a series of unprecedented adverse events in the financial markets," Ernst & Young spokesman Charles Perkins said in a statement that was emailed to MarketWatch. "Our last audit of the Company was for the fiscal year ending November 30, 2007. Our opinion indicated that Lehman's financial statements for that year were fairly presented in accordance with Generally Accepted Accounting Principles (GAAP), and we remain of that view."

"After an exhaustive investigation the Examiner made no findings in his report that Lehman's assets or liabilities were improperly valued or accounted for incorrectly in Lehman's November 30, 2007 financial statements," Perkins added.

Valukas also suggested claims might be possible against some Lehman's competitors, including J.P. Morgan Chase & Co. JPM, +0.96% and Citigroup Inc. C, +1.62% , particularly for demands of about $16 billion in collateral as Lehman began to fall apart.

The report cites, for example, a Sept. 11 call by J.P. Morgan for $5 billion. Read the report here.

A J.P. Morgan spokesman declined to comment.

"Citi is reviewing the Report, which is over 2000 pages long, but notes that, based on its preliminary review, the Examiner has not identified any wrongdoing on Citi's part," a Citigroup spokeswoman said in an emailed statement.