Amid the tumult of a $250 million divorce battle with wife Christine Baumgartner, Hollywood legend Kevin Costner finds himself embroiled in an explosive controversy, with rumors suggesting he sired a child with a Yellowstone TV series crew member.

These startling claims have left the much-loved actor, already grappling with his separation from his wife of nearly two decades, in a state of bewilderment. Baumgartner, adding fuel to Costner's troubled times, refuses to vacate their $145 million oceanfront estate in Santa Barbara.

Costner, 68, who already shares a son, Liam, 27, from a previous relationship with Bridget Rooney, has vehemently denied the allegations of a Yellowstone affair, labeling them as "total BS", according to sources.

An insider disclosed, "Kevin was reluctant to even acknowledge this rumor initially. He and his team view it as utter nonsense, maliciously designed to cause harm at an already difficult time. Despite this, he's left pondering over the origin of these allegations."

Simultaneously, sources hint at a pre-divorce tension, as Costner allegedly lost his cool over Baumgartner's friendship with 42-year-old tech entrepreneur Daniel Starr. Starr, who was renting a beach house on the couple's property for a staggering $64,000 a month, reportedly spent considerable time with Baumgartner when Costner was away on shooting assignments.

However, an insider insisted that Starr never overstepped any boundaries with Baumgartner. Regardless, a disagreement led to a tense text exchange, resulting in Starr's departure in March. Starr maintains he acted as a gentleman throughout his interactions with the couple.

Just under two months post Starr's exit, Baumgartner, mother to three of Costner's seven children – Cayden, 15, Hayes, 14, and Grace, 12 – filed for divorce. Close friends of Costner state he was caught off guard by this decision.

Nevertheless, the shadow of the unverified rumor about Costner fathering another child while away continues to loom large, sparking a frenzy of speculation on social media.

As previously reported, Costner was reportedly devastated when Baumgartner initiated the divorce proceedings. Insiders suggest his demanding work schedule for Yellowstone, where he plays mogul John Dutton, may have strained their relationship.

Meanwhile, legal documents reveal Baumgartner's readiness for a full-fledged legal battle, and her refusal to leave their shared property, which Costner asserts is in violation of their prenuptial agreement.

In the latest turn of events, Costner has proposed providing $30,000 for a rental property and an additional $10,000 for moving expenses, along with extensive child support payments and a $200,000 down payment for a new home.

However, amidst these contentious negotiations, Costner alleges that Baumgartner has racked up $95,000 in legal fees using his credit cards.

The insider shared, "Both Kevin and Christine are determined to fight this battle to the end. It's a truly disheartening situation."