She also indicated she had first heard of the shortfall

Top MF Global executives and burberry ties their lawyers have been meeting with federal authorities investigating the collapse of MF Global and the firm’s misuse of customer money, according to testimony before a Congressional panel on Wednesday.

The testimony, delivered by the firm’s general counsel and two top finance officers, indicated that the federal investigation was progressing five months after the brokerage firm filed for bankruptcy on Oct. 31.

The investigation — led by regulators, federal prosecutors and the Federal Bureau of Investigation — has been constrained because an important MF Global employee had declined to cooperate without first receiving a deal excusing her from criminal prosecution.

That employee, Edith O’Brien, an assistant treasurer of MF Global, continued her silence before the oversight panel of the House Financial Services Committee on Wednesday, as she invoked her constitutional right against self-incrimination. A standoff ensued as lawmakers hurled pointed questions about transfers of customer money that Ms. O’Brien oversaw. But Ms. O’Brien did not take the bait.

“On the advice of counsel, I respectfully decline to answer based on my constitutional rights,” Ms. O’Brien said, appearing to burberry outlet clutch a cross in one hand as she rebuffed lawmakers again and again.

Her silence was not well received by lawmakers.

“We’re extremely disappointed,” said Representative Randy Neugebauer, a Texas Republican who is chairman of the oversight panel. The panel, he said, would consider recalling her and Jon S. Corzine, the firm’s former chief executive, to testify in the coming months.

Ms. O’Brien was excused from the hearing early. She was chased by a throng of reporters as she left the hearing room.

The spotlight then shifted to three MF Global executives who remained: Laurie Ferber, the firm’s general counsel; Henri J. Steenkamp, the chief financial officer; and Christine Serwinski, the North American chief financial officer.

Each executive said he or she was cooperating with the federal investigation into MF Global. Ms. Ferber plans to meet with prosecutors on April 6.

Mr. Steenkamp’s lawyers have offered a so-called proffer statement, an initial but important step in which burberry shoes for men lawyers outline what their client may say in an interview with investigators.

Ms. Serwinski said she had twice met with investigators.

Otherwise, the much anticipated hearing, which was the fifth Congressional forum on MF Global, was short on major revelations. The witnesses repeatedly defended their actions or invoked ignorance about the intricacies of customer accounts.

“I am deeply saddened, upset and frustrated that money belonging to MF Global Inc. customers have not been returned in full,” Mr. Steenkamp said.

He added, “I unfortunately have limited knowledge of the specific movement of funds.”

During the three-hour hearing, lawmakers lambasted the witnesses for their broad denials and claims of ignorance about how more than $1 billion in customer money had disappeared from the firm.

“I appreciate your consistency in having nothing to add,” Representative Michael E. Capuano, a Massachusetts Democrat, said to the witnesses, Ray ban sunglasses eliciting laughter from the gallery of onlookers.

One central focus of the hearing was a suspect transfer of $175 million on Oct. 28 from MF Global to JPMorgan Chase. Ms. O’Brien oversaw the transfer, which was used to patch an account that MF Global had overdrawn at the bank.

Given the myriad ways the bank interacted with MF Global, JPMorgan employees could see the trail of transfers that allowed the brokerage firm to cover its overdraft.

MF Global first withdrew $200 million from customer accounts and placed the money in its own coffers.

The brokerage firm then transferred $175 million of it to cover the overdraft in an account at JPMorgan in London.

The transfer, the bank explained, was not problematic on its face. Futures firms often keep a cushion of cash in customer accounts to facilitate day-to-day operations in the event of situations like market Oakley sunglasses swings, and can draw upon the cushion at will.

But JPMorgan knew MF Global was in distress, and asked the firm’s chief executive, Mr. Corzine, for answers. The conversation set off a back and forth between the bank and MF Global.

“I had great respect for her,” Ms. Ferber said of Ms. O’Brien.

JPMorgan sent three letters to MF Global, each more specific than the last, looking for written confirmation from Ms. O’Brien that the source of the transfer had not violated regulations.

Ms. Ferber, MF Global’s general counsel, told the bank that the first letter was too broad, because it sought assurances about all transfers, not just the ones in question.

Ms. Ferber said she had no reason to believe that burberry sunglasses 2012 customer money was at risk.

A revised letter that mentioned just the transfer of Oct. 28 was finally sent. But Ms. O’Brien, who within the industry was considered an expert of sorts on the subject of protecting customer accounts, never signed it.

A JPMorgan lawyer testifying Wednesday, Diane M. Genova, said that MF Global employees repeatedly had given the bank assurances over the phone that the transfer was not funded by customer money.

Lawmakers on Wednesday asked Ms. Serwinski repeatedly about the wisdom of the transfer.Armani sunglasses for women, cheap armani glasses for men sale.

“Knowing what you know today would you have made that transfer?” Mr. Neugebauer asked Ms. Serwinski, who was on vacation during MF Global’s final week and did not play a role in specific transfers.

“No,” she replied.

In her written testimony, Ms. Serwinski said that there had been red flags regarding customer funds as early as Thursday, after the firm had burned through a buffer of money protecting customer funds. She also indicated she had first heard of the shortfall on Saturday, Oct. 29, a day before regulators were told of the shortfall.

Representative Michael G. Fitzpatrick, Republican of Pennsylvania, asked Ms. Serwinski, who cut her vacation short to return to the firm on the evening of Oct. 30., why she had not told any of the regulators when cheap louis vuitton mens shoes she became concerned.

“We did not believe it was a deficiency at that point,” she replied.