Kevin Costner's Ex Claims His 'Vast Estate' Grew from $100M to $400M During Their Marriage

Kevin and Christine Costner got married in 2004 with a prenup in place

Kevin Costner’s estranged wife Christine believes her husband’s “vast estate” quadrupled in value from $100 million to $400 million during the course of their 18-year marriage.

The claim comes as Christine and Kevin battle over the premarital agreement they signed ahead of their 2004 wedding. According to legal documents filed by Kevin, Christine — who filed for divorce on May 1 — is entitled to a $1.5 million payout under the agreement, which she risks forfeiting by challenging the terms.

In documents filed in California Superior Court Aug. 23 and obtained by PEOPLE, an attorney for Christine, 49, responded to Kevin’s Aug. 10 request for order, in which he asked the court to compel his ex to answer certain questions regarding her understanding of the premarital agreement. The trial to determine the agreement's validity is set for November.

The attorney for Christine asked the court to reject Kevin’s request, stating that their client is unable to say whether or not she had a “full and fair” disclosure of his assets at the time they signed the agreement.

Her legal team also reiterated their stance that they are challenging portions of the agreement, including the “spousal support limitation,” saying that it was “unconscionable at the time of enforcement.”

Related: Kevin Costner 'Does Not Know for a Fact' If Ex Christine Had Affair but 'He Engaged in None'

“In July 2004, Kevin’s financial disclosure attached to the PMA consisted of 15 pages of bank accounts, investments, retirement accounts, real estate, land holdings, investments in closely held businesses, other assets, and liabilities. Kevin’s total assets at the time were $102,716,000,” the lawyer wrote.

“Christine is unable to answer whether Kevin’s disclosures in 2004 were ‘full and fair’ until she has had the opportunity to conduct discovery as to his financial circumstances at that time. For example, if Christine were to discover that Kevin had substantial funds in an undisclosed offshore bank account at the time she executed the PMA, this would impact her response to these requests,” the lawyer continued.

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Marilyn B. Chinitz, a New York matrimonial and family law attorney at Blank Rome who is not connected to this case, tells PEOPLE that “every move is strategy.”

Christine, continues Chinitz, “is saying, ‘Look, I don't know whether or not I could admit that I had full disclosure. Maybe you didn't tell me everything.' ”

In a footnote in these latest documents, Christine’s lawyer also stated that “although we have not completed formal discovery, we believe that Mr. Costner’s net worth is in excess of $400,000,000 and his own forensic determined that his 2022 cash available for support was in excess of $24,000,000.”

Chinitz says the increase in value of Kevin’s assets should be “irrelevant” since Christine signed the premarital agreement.

Related: A Complete Timeline of Kevin Costner and Christine Baumgartner's Divorce

“Yes, there's something fundamentally unfair about the fact that she doesn't get much more and his assets have grown exponentially for whatever reason. But that's the bargain you struck,” says Chinitz.

However, Christine could still see a “positive outcome,” according to Chinitz.

“If she's asking the court to award her more support, because the amount that is provided in the agreement is unconscionable — given the fact that her assets are going to be diminished as compared to his — the court can actually say yes, we're going to sever that provision in the agreement. And we're going to look at the issue of support, how much you need, what would sustain your lifestyle somewhat consistent with the way you and your children have lived,” Chinitz continues.

Christine's attorney also asked the court to have Kevin pay around $8,000 in legal fees Christine accrued while responding to Kevin's request.

The exes share three teenagers: Cayden, 16, Hayes, 14, and Grace, 13. Christine was temporarily awarded $129,755 per month in child support in July. An evidentiary hearing related to the child support payments is scheduled for next week.

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