The sister of fraudster Bernie Madoff, who was convicted of masterminding the largest known Ponzi scheme in history, and her husband died last week from an apparent murder-suicide, authorities said on Sunday.

Madoff's sister, Sondra Wiener, 87, and her husband Marvin were found with gunshot wounds on Thursday in Boynton Beach, Florida, according to a statement from the Palm Beach Sheriff's Office.

"After further investigation it appears to be a murder/suicide," the office said. The medical examiner will determine the cause of death.

Madoff died at age 82 last year in federal prison, where he was serving a 150-year sentence.

His massive scheme, estimated as high as $64.8 billion, went undiscovered for years and ensnared thousands of victims, including charities, hedge funds, celebrities and pension funds.

A view of Yeshiva University
A view of Yeshiva University (credit: SCALIGERA/ENGLISH WIKIPEDIA)

Madoff's victims included Yeshiva University, where he served as the treasurer of the Board of Trustees and which lost over $100 million; the Jewish Community Foundation of Los Angeles with losses of $25.5 million; and Washington’s Jewish Federation, which was bilked of $10 million. The Ramaz day school in New York lost over $5 million, while the American Jewish Congress found that about two-thirds of its nearly $17 million endowment was gone.

Madoff also reportedly scammed Elie Wiesel’s charitable foundation out of over $36 million. The Wall Street Journal reported that Steven Spielberg’s charity, the Wunderkinder Foundation, invested nearly 70% of its money with Madoff, most of which was lost. And Fred Wilpon, the Jewish owner of the New York Mets, was forced to pay $162 million in restitution, eventually forcing him to sell the team.