“The case against the defendant is strong and it continues to grow stronger as the government’s investigation continues,” Mr. Litt said. “Given the defendant’s age, the length of the likely sentence, the strength of the proof against the defendant, including his confessions, these facts present a clear risk of flight.”

Ira Lee Sorkin, a lawyer for Mr. Madoff, said at the hearing that Mr. Madoff had not meant to violate the agreement and should not be sent to jail. Mr. Madoff is not a flight risk, and he and his wife tried to recover the valuables after speaking to their lawyers and realizing they should not have mailed them, Mr. Sorkin said.

Image H. David Kotz of the S.E.C. and Stephen P. Harbeck, head of the Securities Investor Protection Corporation. Credit... Richard Perry/The New York Times

But speaking after the hearing, Mr. Sorkin disavowed his earlier statements that Mr. Madoff was cooperating with prosecutors and F.B.I. agents seeking to unravel the Ponzi scheme.

“No one ever said he was cooperating with the government,” Mr. Sorkin said — though he had previously said that “we” were helping investigators from the F.B.I. and the S.E.C. Mr. Sorkin said he had meant that Mr. Madoff’s firm, Bernard L. Madoff Investment Securities L.L.C., was cooperating with the investigation.

Mr. Madoff told F.B.I. agents last month that he had overseen a financial fraud that had cost investors as much as $50 billion, according to a criminal complaint filed in federal court in Manhattan. The fraud was continuing just days before Mr. Madoff confessed it to the F.B.I., according to a lawsuit filed by a New York company that claims Mr. Madoff took in $10 million from it on Dec. 5.

A government-appointed receiver has now taken over his firm, and S.E.C. agents and F.B.I. investigators are conducting a far-flung investigation to see who might have aided Mr. Madoff. On Monday, the trustee overseeing the liquidation of Mr. Madoff’s firm sent 8,000 claim forms to people who may have invested with Mr. Madoff, asking them to detail what they believe they are owed.