Kate and Oliver Hudson are considered "dead" to their father Bill Hudson.
The 65-year-old actor - who has three other children - has requested the 36-year-old 'How To Lose A Guy In 10 Days' star and 38-year-old 'Rules of Engagement' actor - who he fathered with actress Goldie Hawn - stop using the surname Hudson, as he doesn't consider them to be his after their hurtful posts on Twitter on Father's Day.
At the time, along with a picture of Bill with the two siblings as young children, Oliver posted to his sister: "Happy abandonment day..."
Bill has now said: "I say to them now, 'I set you free'. I had five birth children but I now consider myself a father of three. I no longer recognise Oliver and Kate as my own.
"I would ask them to stop using the Hudson name. They are no longer a part of my life. Oliver's Instagram post was a malicious, vicious, premeditated attack. He is dead to me now. As is Kate. I am mourning their loss even though they are still walking this earth."
Bill went on to insist that he and Goldie didn't part on bad terms in 1980, after being married for four years, and it was only after she got together with Kurt Russell in 1983 that things turned sour.
Speaking to the Mail on Sunday newspaper, Bill said: "When we split up, she never had a bad word to say about me. But when Kurt came on the scene, the narrative changed and I became the big, bad wolf. I would say to her, 'Goldie, why are you trashing me and saying I'm an absent father when it's simply not the case?' and she'd laugh and go 'Oh Bill, you know it makes for a better story'."
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