Kurt Russell has opened up about Oliver Hudson’s relationship with biological father, after a cruel Instagram caption escalated into an all-out family war.

Russell — the longtime partner of Oliver and Kate Hudson’s mum, Goldie Hawn — said the family is on the mend.

“I understood Oliver’s sense of humor and since then, there’s been some nice back and forth between Bill and Oliver that’s nice to see,” "The Hateful Eight" star told E! News.

“You want people to enjoy life as much as they can. We live in a world that if you say something or do something, it can be latched onto [you] for 24 hours or 48 hours.”

Oliver and Kate Hudson have made it clear they are not close to father Bill Hudson and instead consider Russell, 64, their father.

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But on Father’s Day, Oliver rubbed salt in the wound by posting an image of him and his sister flanking Bill, with the caption: “Happy abandonment day”.

Deepening the hurt, 38-year-old Oliver posted a second image of himself with Russell with the words: “Happy Father’s Day, Pa”.

Kate, 36, also posted an image of herself with Russell to Instagram, accompanied by the message: “Pa, just simply ... thank you. Happy Father’s Day. I love you to the moon and back.”

A photo posted by Kate Hudson (@katehudson) on

In an exclusive interview with Britain’s The Mail on Sunday, Bill accused ex-wife Goldie Hawn of turning their children against him, “willfully alienating” him from them for the sake of a “better story”.

“Goldie wanted to create this myth of a perfect family with Kurt and she wanted me out,” he said.

Bill and Hawn divorced in 1980, and Hawn and Russell began their relationship in 1983.

“When we split up, she never had a bad word to say about me,” he said.

“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’.”

For Bill, the recent public act of disrespect was the last straw.

“I say to them now, ‘I set you free’,” he told the Mail.

“I had five birth children but I now consider myself a father of three. I no longer recognize 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.”

This article originally appeared on News.com.au.