A Long Island man claims a local dog shelter that took in his lost Belgian Malinois refused to give it back — and then adopted it out to another family, according to a new federal lawsuit.

Brentwood resident Clifton Benjamin, who works as a TSA canine handler, purchased his prized pooch Eto from a breeder in the Netherlands and was in the process of socializing and training the dog when it got loose on Sept. 18, 2018, according to the suit filed late last week in the Eastern District of New York.

The dog — which is the same breed as Conan, the military working dog that took down ISIS leader Abu Bakr al-Baghdadi — was swiftly brought to the Town of Islip animal shelter where Benjamin showed up the next day to pick him up, according to the lawsuit.

He provided proof of ownership to staffers at the shelter but was told they needed more evidence and they couldn’t give Eto back to him, the filing states.

Benjamin then sent the shelter more documents via email, including copies of conversations he had with the owner of Eto’s litter mate, pictures of him with the dog and copies of shipping information from the Netherland’s breeder, and was told the town’s lawyer would review the documents and have an answer for him shortly.

The doggy dad followed up with the shelter three more times over email, to no avail, and finally showed up on Oct. 14 — where he was told the pooch had already been adopted by another family, the lawsuit states.

“This was a ruse, scam, and a scheme, orchestrated by the Town of Islip, the animal shelter, its agents/employees/members, to wrongfully deprive/convert/steal and otherwise trespass upon the chattel of Plaintiff, by falsely telling Plaintiff he needed to provide more proof that he owned the dog, so as to enable Defendants to smuggle the dog out to a private adoption, for an undisclosed sum,” the filing alleges.

Fully trained Belgian Malinois dogs can sell for between $20,000 and $40,000, the suit states.

Benjamin, who purchased the dog for breeding purposes but also for personal companionship, said he is yet to be reunited with his pet and is suing for $1 million in damages, according to the suit.

The Town of Islip slammed the lawsuit as “frivolous” and insisted Benjamin never provided proper documentation for Eto.

“There were multiple claims for the dog, none of whom could prove ownership. The plaintiff had no physical paperwork in his name, and what he did have, included inaccurate information including a chip number that did not match the chip number in the dog,” a spokesperson for the town wrote in an email.

“The plaintiff admitted to giving the dog to a third party. The dog was brought in on September 14th, 2018 and adopted on October 5, 2018. We received several inquiries. We did more than our due diligence in looking for a responsible owner. The dog was ultimately adopted out to a retired NYC police officer with no relationship to the Town of Islip.”