NEW YORK (

TheStreet

) --

JPMorgan Chase

(JPM) - Get Report

and

Citigroup

(C) - Get Report

helped cause the failure of

Lehman Brothers

by demanding more collateral and changing guarantee agreements, says a

Bloomberg

reading of a court-ordered report on the biggest bankruptcy in U.S. history.

"The demands for collateral by Lehman's lenders had direct impact on Lehman's liquidity," said Anton Valukas, the bankruptcy examiner, in the document filed Thursday. "Lehman's available liquidity is central to the question of why Lehman failed."

Danielle Romero-Apsilos, a spokeswoman for Citigroup, said in an e-mailed statement to

Bloomberg

that the bank is reviewing the report, and that a preliminary analysis shows the examiner "has not identified any wrongdoing on Citi's part."

The report has pulled up former Lehman CEO Richard Fuld and ex-Chief Financial Officer Erin Callan, among others, for certifying misleading statements about the bank's finances.

Valukas said Fuld was "at least grossly negligent in causing Lehman to file misleading periodic reports" while its risks were rising because of long-term assets financed with short-term debt.

Disputing the examiner's allegation, Fuld's lawyer, Patricia Hynes, told

Bloomberg

, "Mr. Fuld did not know what those transactions were -- he didn't structure or negotiate them, nor was he aware of their accounting treatment."

Valukas also made a mention of

Barclays

(BCS) - Get Report

purchase of Lehman's North American brokerage that a "limited amount of assets" belonging to Lehman were "improperly transferred to Barclays." He added that the value of the assets may not be "material."

Spokespeople for Barclays and JPMorgan spokesman declined to comment for Bloomberg.