Twelve members of a single family were charged Thursday with lying to lenders to obtain more than $20 million in mortgage loans while claiming poverty to collect food stamps and other government benefits over the past decade in what federal authorities call "sweeping and cynical fraud."

An indictment unsealed in federal court in White Plains Thursday charged real estate developer Irving Rubin and his relatives with conspiring to commit bank fraud and conspiring to make false statements. It alleged that family members used the proceeds to pay their credit card debts and their own home mortgages and to fund other real estate projects.

The defendants include Rubin, his wife, two sons, three brothers and five in-laws. A lawyer and an appraiser also were charged.

Sources told NBC 4 New York that 13 suspects were arrested in Brooklyn and Kiryas Joel, an Orange County village, and two others surrendered to authorities Thursday. Authorities also served search warrants and seized 23 properties worth a combined $50 million.

"As alleged, the scheme carried out by the Rubins and others ripped off banks, welfare programs, and taxpayers," U.S. Attorney Preet Bharara said. "It ranged from 2004 to 2014, from Brooklyn to Harlem to Orange County, and the individuals involved alternately played the parts of prince or pauper, depending on which scam was being perpetrated."

There was no immediate information on defense attorneys.

The indictment alleged family members lied to lenders about their assets, income, employment and primary residence to obtain mortgages on at least 18 properties they claimed to own, most of them in Brooklyn.

The alleged lies gave "the false appearance of creditworthiness, when in fact the assets and/or bank accounts were nonexistent" or were not fully owned by the applicant, the indictment said.

It said they "engaged in extensive efforts to perpetuate and conceal" the scheme. For example, some of the defendants allegedly made sham transfers among themselves, "thereby confounding attempts by lenders to recover on defaulted loans," the indictment said.

Several defendants also were charged with fraudulently receiving hundreds of thousands of dollars in food stamps, Medicaid and home-heating help.

"At the same time that the defendants were representing to banks that they had substantial income and assets, they were also representing to state and local agencies that they had little or no income and assets and were eligible to receive various forms of public assistance," the indictment said.

FBI Assistant Director George Venizelos called it a clear case of "double dipping."

"The defendants convinced lenders of their affluence while allegedly accepting aid from government programs established for the benefit of those less fortunate," Venizelos said.

Some of the family members claimed one income on government assistance forms, while vastly overestimating their income to secure large bank loans, officials say. In one instance, one of Rubin's relatives claimed weekly income of $200 to get Medicaid and food stamps while claiming a net worth of $10 million to banks in order to get $7 million in loans.

"Whether posing as rich men or poor men, they were always con men," Bharara said.

The suspects pleaded not guilty in court Thursday; most were released on bail.