Kevin Costner accuses estranged wife of using 'stalling tactics' to drag out the pair's increasingly acrimonious divorce

• Kevin Costner accused his wife Christine Baumgartner of intentionally prolonging their divorce.
• In a Thursday filing, Costner said his ex has "thrown roadblock after roadblock up."

After months of back and forth between their lawyers, Kevin Costner has accused his estranged wife Christine Baumgartner of deliberately trying to prolong their divorce proceedings.

Since they began battling it out, the premarital agreement that they signed upon their 2004 marriage has been at the heart of their increasingly contentious divorce.

Costner claimed in a new filing obtained by Insider that he served his soon-to-be ex-wife with a "very basic" written discovery request related to their prenup agreement shortly after she filed for divorce in May citing "irreconcilable differences."

Now, Costner, 68, requested financial sanctions against Baumgartner, 49, for failing to respond to the requests and called her out for trying to "delay" their divorce.

"Christine has only thrown roadblock after roadblock up in an unjustified effort to avoid answering this discovery," his lawyer wrote in an August 10 filing.

"Monetary sanctions in the amount of not less than $14,237.50 should be ordered paid by Christine to Kevin," Attorney Amy Rice wrote. "Discovery is not a game of chicken."

The "Yellowstone" actor said that Baumgartner has "steadfastly refused" to disclose her divorce contentions in the four months that have passed.

As an example of his estranged wife's dilatory tactics, Costner pointed to the fact that her legal team had asked for a definition of the word "understood" after his attorney Laura Wasser asked whether Baumgartner "understood the legal effect of the premarital agreement before you signed the premarital agreement."

"This is gamesmanship of the worst sort," an attorney for Costner wrote. "'Understood' is not a technical or arcane word."

"The notion that Christine and the multiple seasoned lawyers representing her do not understand the word 'understood' and cannot reply to this simple, straightforward [request for admission] is frivolous," the lawyers said. "Clearly, this vagueness objection was interposed only for the purpose of delay."

A hearing to determine the prenuptial agreement's validity has been scheduled for November.

Costner landed one early legal victory after a Santa Barbara county judge ordered Baumgartner to move out of the former couple's $145 million beachfront property, per a clause set out in their prenuptial agreement from their 2004 marriage.

Last month, the couple's child support payment dispute was settled, with Costner agreeing to pay his soon-to-be ex-wife $129,755 per month until the divorce is finalized — much lower than Baumgartner's original request of $248,000 a month, but still far more than what his legal team proposed.

In late July, Baumgartner made good on her promise to vacate the former couple's home but only moved so far as a smaller house on the compound typically used as staff quarters, according to People.

Lawyers for Costner and Baumgartner did not immediately respond to requests for comment.