And the two former BFF actresses' relationship deteriorated when Hudson began seeing rocker Matt Bellamy, and "it made Kate believe she is rock and roll royalty and the next Gwyneth Paltrow," the source added.
Hudson, 35, and Alba, 33, who both have two kids, became inseparable after co-starring in the 2010 film The Killer Inside Me but "Kate has wrecked the friendship and Jessica pins the start of their troubles to the beginning of Kate's relationship with Matt a few years ago."
The Almost Famous actress is engaged to Bellamy and recently celebrated her birthday dressed in a revealing jump suit with stars such as Demi Moore, Reese Witherspoon, and rock star wife Nicole Richie, cheering her on at No Name Bar in Hollywood. But Alba was nowhere in sight!
"Unfortunately, Kate has become not a nice person since she's been with Matt," the source said. "It's sad but Kate and Jessica's friendship is completely done. They used to be so close, too."