Senior executives at JPMorgan Chase expressed serious doubts about the legitimacy of Bernard L. Madoff's investment business more than 18 months before his Ponzi scheme collapsed but continued to do business with him, according to internal bank documents made public in a lawsuit unsealed on Thursday, according to a story in today's edition of The New York Times by Diana B. Henriques.

On June 15, 2007, an obviously high-level risk management officer for Chase's investment bank sent a lunchtime e-mail to colleagues to report that another bank executive "just told me that there is a well-known cloud over the head of Madoff and that his returns are speculated to be part of a ponzi scheme," the article said.

"Even before that," the article continued, "a top private banking executive had been consistently steering clients away from investments linked to Mr. Madoff because his 'Oz-like signals' were 'too difficult to ignore.' And the first Chase risk analyst to look at a Madoff feeder fund, in February 2006, reported to his superiors that its returns did not make sense because it did far better than the securities that were supposedly in its portfolio."

"Despite those suspicions and many more, the bank allowed Mr. Madoff to move billions of dollars of investors' cash in and out of his Chase bank accounts right up until the day of his arrest in December 2008 - although by then, the bank had withdrawn all but $35 million of the $276 million it had invested in Madoff-linked hedge funds , according to the litigation," the article said.

"The lawsuit against the bank was filed under seal on Dec. 2 by Irving H. Picard, the bankruptcy trustee gathering assets for Mr. Madoff's victims. At that time, David J. Sheehan, the trustee's lawyer, bluntly asserted," the article said, "that Mr. Madoff ' would not have been able to commit this massive Ponzi scheme without this bank.'"

The bank and the trustee mutually agreed to unseal the complaint. The lawsuit is one of hundreds the trustee has filed to recover assets for the victims of the Ponzi scheme. To date, the trustee has collected about $10 billion through settlements and asset sales.

In a statement released yesterdat, a Chase spokeswoman said the trustee's complaint was "based on distortions of both the relevant facts and the governing law. Contrary to the trustee's allegation, JPMorgan did not know about or in any way become a party to the fraud orchestrated by Bernard Madoff."

"Madoff's firm," the bank's statement continued, "was not an important or significant customer in the context of JPMorgan's commercial banking business, and the revenues earned from Madoff's bank account were modest and entirely consistent with conventional market rates and fees." The trustee's claims that the bank earned extraordinary sums from its Madoff relationship "is demonstrably false," the statement continued.

Although lawyers redacted the names and specific positions of bank executives involved the incidents described in the lawsuit, other information in the complaint makes it clear that many of them held prominent positions.

Deborah Renner, one of the Madoff trustee's lawyers with Baker & Hostetler, reinforced that impression in a statement released Thursday. Ms. Renner said, "Incredibly, the bank's top executives were warned in blunt terms about speculation that Madoff was running a Ponzi scheme, yet the bank appears to have been concerned only with protecting its own investments." One discussion of the bank's "due diligence" on Mr. Madoff was aired on June 15, 2007, at a meeting of the bank's Hedge Fund Underwriting Committee. According to the complaint, that committee was "comprised of senior business heads and bankers, including individuals such as the chief risk officer and the heads of equities, syndicated leveraged finance, sales, and hedge funds."