An "ironclad" prenuptial agreement could block Hugh Hefner's wife, Crystal Harris, 31, from inheriting anything from his estimated $43 million fortune.

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Hefner passed away peacefully in his home, surrounded by loved ones, on Sept. 27. He was 91 years old.

The model and the late media tycoon tied the knot on New Year's Eve in 2012, and soon after, a source told Us Weekly that Harris signed a prenuptial agreement and was not added to Hefner's will, according to a 2013 report.

At the time of the report, Hefner’s fortune was promised to “his children, the University of Southern California film school and a variety of charities,” according to a source, who added that Harris would be “taken care of.”

Harris broke things off five days before their planned June 2011 wedding, and ahead of their 2012 wedding, she explained why she got cold feet before the first planned nuptials:

"Last time it turned into a a big ordeal, and then it all fell apart," she said at the time. "This time around is amazing ... I'm very happy, and Hef's very happy and we're excited."

Harris is Hefner’s third wife. He was previously married to Mildred Williams in 1949 before divorcing 10 years later; in 1989, he married Playmate Kimberly Conrad, but the two separated in 1998 and divorced in 2010.

Hefner is survived by four children. His final wishes or any recent updates to his will were not immediately clear.

Los Angeles, CA - OCTOBER 25:  Hugh Hefner and Crystal Hefner attend Playboy Mansion's Annual Halloween Bash at The Playboy Mansion on October 25, 2014 in Los Angeles, California.  (Photo by Charley Gallay/Getty Images for Playboy)

Credit: Charley Gallay

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Credit: Charley Gallay