An Upstate New York man fears his squirrel was decapitated after state agents seized the rodent from his home — as a funeral takes place for the internet-famous creature.

P’Nut’s grieving owner Mark Longo told The Post he is planning a lawsuit against the state Department of Environmental Conservation after they raided his home, took the squirrel and euthanized it to test for rabies.

“I hope to give him a proper burial,” Longo told The Post of P’Nut’s final rites, which will take place at a fully functioning human funeral home that is making its space available for free.

‘But seven days later the body has still not returned. There are no known results from tests for rabies.”

The DEC claimed it was forced to perform rabies testing on P’Nut and Longo’s raccoon, Fred, and those tests require a sample from the subject’s brain.

It’s a prospect that makes Longo shudder to think about it, and one he’s willing to sue for.

“This is much bigger than a squirrel and a raccoon. This is about government overreach,” he said. “We want justice for what happened at my home. You violated my home. You killed my animals.”

P’Nut – a squirrel with a penchant for proportionate cowboy hats – was raised in their home by Longo and his wife for seven years since they rescued him as an orphaned puppy.

After rehabilitating the helpless animal for eight months, they released him, but he refused to leave, so they took him in full-time, the couple said.

During those years, the squirrel amassed a following on social media and inspired the Longos to move from Connecticut and open a 350-acre animal shelter in upstate Pine City.

But that all came crashing down in October when the DEC showed up in response to an anonymous complaint about the Longos who housed P’Nut and Fred in their home, and after tearing the house apart, left with the animals. P’Nut reportedly bit one of the officers on the hand during the operation, prompting the DEC to euthanize both animals.

And Longo hasn’t heard a word from the DEC since.

“I was told by a news station that my animals were being killed,” Longo said. “I, as a citizen of New York, had my animals killed by my own government, and my own government couldn’t call me to tell me what happened. I had to read it in a newspaper.

“Someone must be held accountable for the massive overreach of power,” he added.

Longo has already hired an attorney, Nora Marino, and hopes anyone who has had a similar situation with the DEC will reach out as they prepare their lawsuit.

“If it happened to you – if you know someone who it happened to – please contact us, we need to call for action,” Longo said.

“What’s to stop the average Joe from calling now and complaining about your neighbor? If you complain enough, can you get a search warrant? When does it end?”

For the next few days, though, Longo is just focusing on putting his furry friends to rest, with a service possibly taking place as soon as Saturday at a funeral home in Elmira.

“This should never have happened. But in a way I’m glad it worked out. Because it gave Peanut the voice to shed light on what is going on in our government,” he said.

The DEC declined to comment, citing pending litigation when contacted by The Post.