The head of the private exchange tasked with overseeing MF Global said Tuesday that Jon Corzine may have been aware of a transfer of client funds from the firm he formerly led, possibly contradicting the former governor and senator’s statements under oath that he had no knowledge of the events that resulted in the disappearance of $1.2 billion in customer funds.

In a hearing before the Senate Committee on Agriculture, Nutrition and Forestry, Terrence A. Duffy, the chief executive of CME Group, said a senior female executive of MF Global told a CME auditor that Corzine — the former chief executive officer and chairman of the firm — was aware of a $175 million loan of customer money to a European affiliate of the now-bankrupt commodities brokerage.

“Mr. Corzine was aware because our employee had heard this, on the phone—‘Send back 175’ — and said he was aware of this loan,” Duffy told the Senate committee.

Corzine resigned from MF Global in early November after a disastrous week in which the firm lost two-thirds of its market value, filed for bankruptcy protection and found itself the target of investigations by the FBI, the Commodity Futures Trading Commission and the Securities and Exchange Commission as a result of the funds vanishing.

Corzine has denied involvement in any illegal or improper movement of funds. In comments Thursday, he said his remarks could have led to a “misunderstanding” about the customer money. “I never directed anyone at MF Global to misuse customer funds. I never intended to, and as far as I’m concerned, I never gave instructions that anyone could misconstrue,” Corzine said Tuesday.

Duffy said earlier that segregated customer funds had been illegally and improperly transferred Oct. 27 and 28, describing the transfers as “disguised from all regulators.” In his prepared remarks, Duffy said, “Somebody went in and violated the rules of the CME and the rules of the government.”

Duffy didn’t elaborate on the exact nature of the $175 million loan that Corzine had allegedly known of, or whether that specific loan was among those that were illegal and improper. Futures firms are required to segregate customer money from the firm’s own funds, though there are circumstances under which moving customer money is permitted, provided there is sufficient collateral.

“The only thing I can tell you [is] that MF Global transferred customer money to its broker dealer, and that Mr. Corzine was aware of the loans being made from segregated accounts,” he said. When asked for elaboration, a CME spokesman said the firm would not comment beyond the remarks Duffy made at the hearing.

The accusations could end up contradicting statements that Corzine had made just hours earlier during the same hearing, when he denied any knowledge of what happened to segregated customer funds that had vanished until the early hours of Oct. 31, when he and other top MF Global executives heard the news.

Corzine’s spokesman, Steve Goldberg, had no comment on the allegations.