Earlier this summer, billionaire hedge fund manager Kenneth C. Griffin filed for divorce from his wife of 11 years, Anne Dias Griffin. Many observers were surprised by this development, and the financial media have been waiting for the next shoe to drop. Anne Griffin did not disappoint, as on September 2nd she responded to her husband’s divorce petition by filing a request for sole custody of their three children and for permission to move to New York.

Anne Griffin

The major surprise, however, was news of a filing that the prenuptial agreement signed by the couple back in 2003 was signed under duress and should therefore be voided.

These court filings appear to signal that the breakup of the Griffins, one of the Windy City’s most prominent power couples, will evolve from a quiet domestic dispute into a nasty public brawl. The situation developing into an acrimonious courtroom fight is not that surprising given that when Citadel founder Griffin filed for divorce in late July, Ms. Griffin claimed that she had not been forewarned of her husband’s intentions.

Ken and Anne Griffin’s complicated separation

Despite apparent domestic calm just before the divorce filing, with the pair making appearances together at social events, in actuality things were more complicated. In one of the filings, Ms. Griffin disclosed that her husband moved out in February 2012 and has spent minimal time with the children.

Ms. Griffin also claimed she was on her way to the airport with the children to take a vacation when she was informed of the divorce petition. The filing noted that while she was gone, Ken Griffin had furniture and valuable pieces of art removed from their home in Chicago

More on Anne Griffin filing to void prenup

Anne Griffin key legal move is her effort to overturn the prenuptial agreement, signed the day before the couple’s wedding in Versailles in the summer of 2003. Ms,Griffin claims Mr. Griffin did not mention a prenup agreement until “shortly” before the wedding, catching her off guard with a document for her signature.

Moreover, he dis not disclose his financial details until July 16 of that year, three days before the wedding.  According to the filing, the couple had an intense argument that day during which Mr. Griffin broke a piece of furniture.

Afterwards, Mr. Griffin suggested that the couple see a psychologist, but he did not disclose that he was already a patient of the therapist. During the session on July 17, the psychologist recommended that Ms, Griffin go ahead and sign the prenuptial agreement despite her misgivings.

“As a result of Kenneth’s actions as described above, Anne was unduly influenced by Kenneth and the psychologist under the guise of a counseling session with a neutral psychologist,” the filing noted. “Upon information and belief, Kenneth’s purpose for arranging the therapy session with Anne and the psychologist was to convince Anne to sign his agreement.”