A new biography claims Madonna’s daughter, Lourdes, was at the center of the explosive fallout between Gwyneth Paltrow and Madonna.

In Gwyneth: The Biography by Amy Odell, the Oscar winner’s private life takes the spotlight, including her once-tight bond with the pop legend that crumbled after a tense encounter involving Lourdes.

Paltrow and Madonna were famously close in the late 1990s and early 2000s, vacationing together, working out side by side, and attending Kabbalah classes. According to the new book, the friendship took a sharp turn during a group trip where Madonna’s behavior toward her daughter allegedly shocked Paltrow and her then-husband, Chris Martin.

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“Madonna seemed to know that Gwyneth would be there, which Gwyneth seemed to find strange,” a friend told Odell.

At a group dinner, Madonna reportedly lashed out at Lourdes in front of everyone, leaving Paltrow and Martin appalled.

“Gwyneth and Martin were disgusted by the behavior,” Odell wrote.

Martin later called Madonna “awful” and reportedly told Paltrow he “can’t be around this woman anymore,” according to the biography.

Paltrow reportedly agreed, labeling Madonna “toxic” and ultimately ending the friendship.

The fallout marked a stark shift from just a few years earlier, when Paltrow openly praised Madonna.

In a 2006 US Weekly interview, the Shakespeare in Love actress described Madonna as “like her older sister,” adding, “Everything I have gone through, she went through ten times worse and ten times longer. She gives me good advice about how to say no and take care of myself.”

But by April 2010, cracks in the long relationship were showing.

Speaking to British Vogue, Paltrow made a pointed remark about her then-business partner and celebrity trainer Tracy Anderson, saying, “Yeah, it’s good that [Tracy] doesn’t train Madonna any more. It was too much. She keeps people waiting, it takes up your whole day.”

While the book doesn’t specify when the alleged vacation incident took place, Odell’s account sheds new light on the behind-the-scenes tension.

Paltrow and Madonna have not been seen together in public since 2010.

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