Updated

Prosecutors stepped up their scrutiny of Bernard Madoff's family and assets Tuesday, telling a judge they want to seize jewelry, business interests and more than $30 million that the disgraced money man and his wife lent to their two sons.

The move was one of two motions that prosecutors filed Tuesday, four days after Madoff pleaded guilty to what could be the largest fraud in history. The other motion argued that Madoff must remain behind bars before his sentencing because his guilty plea creates a tremendous motive to flee, especially since he faces the near-certainty of a life prison sentence.

Assistant U.S. Attorney Lisa A. Baroni said strict bail conditions that have kept Madoff under guard in his apartment with an electronic ankle bracelet and video monitoring were not foolproof. She said Madoff "managed to perpetrate an enormous fraud, over the course of decades; his ingenuity should not be underestimated."

The prosecutor even noted that Madoff "has been shunned by the New York community and his inability to salvage his reputation." She said his history of extensive foreign travel, including to his $1 million home in France, also heightened the risk he could flee.

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Click here to read the judge's decision at FindLaw.

The court filing sets the stage for arguments Thursday before a federal appeals court on whether Madoff should remain jailed. His defense lawyers have asked the court to set him free ahead of his sentencing.

The bail issue was one of two fronts for prosecutors in the Madoff case Tuesday. They are also pursuing the fruits of the fraud, attempting to seize as many assets from Madoff as they can to reimburse victims who lost billions.

The government earlier this week indicated it will seek the forfeiture of nearly everything the Madoffs own, from the $22 million estimated value of four homes to $62 million in cash and securities, nearly all of it in the name of Madoff's wife, Ruth.

The latest list extends the demands to loans the Madoffs made to their sons, Mark and Andrew, including an Oct. 6 promissory note for $4.3 million to Andrew and a Sept. 21 note for $250,000 to Andrew. The loans came less than three months before Madoff admitted to them that his investment business was a complete fraud.

In all, the government cites $22 million in loans to Mark and $9.55 in loans to Andrew. The document lists 2005 as a particularly busy year, when Mark received $16 million in loans and Andrew received $5 million in loans.

Madoff has insisted that his family was not involved in the fraud, but the attempt to seize the loans is a sign that prosecutors are intensifying scrutiny of the sons as they investigate how the scam was carried out.

Prosecutors are also going after Madoff's business interests. The businesses in which the Madoffs would have to relinquish any ownership interest include real estate partnerships, a New Jersey cancer clinic and PJ Clarke's on the Hudson, a tavern located in the financial district.

Gary Berger, the administrator at Hoboken Radiology, said Ruth Madoff had bought a 21.25 percent interest in the business about five years ago through an investor who was a personal friend of Madoff.

Berger said the Madoffs never visited the facility and he had never met them, though he had arranged the financing.

"I'm happy they're looking at her assets," Berger said. "If she received her assets due to Bernie Madoff's Ponzi scheme, obviously there's something wrong with that."

He said the facility serves between 125 and 150 people per week, including cancer patients.

The filing also says Madoff has a stake in several entities of Sterling American Property, a real estate investment firm that also has ownership interests in the sports world.

Company spokesman Richard Auletta said in a statement that "no member of the Madoff family has any affiliation with or interest or investment in Sterling Equities, the New York Mets or Sports Net New York."

Auletta said that Ruth and Peter Madoff invested "as passive limited partners in real estate funds sponsored by the partners of Sterling Equities, as well as a limited number of other venture capital type investments in which the partners of Sterling Equities have an interest."

"Any potential forfeiture of these investments will have no material impact on such ventures," he said.

Prosecutors say Madoff told 4,800 investors in his private securities investment business in November that their investments were worth nearly $65 billion. Investigators hunting for assets say they have found about $1 billion in assets.