The older man suspected of murdering a 33-year-old New York City artist at a swanky Hamptons spa was found dead of an apparent suicide, police said Wednesday. 

Thomas Gannon, 56, died from a self-inflicted gunshot wound at his home in Honesdale, Pa., 214 miles from the crime scene, according to the Suffolk County Police Department.

Police said Gannon and Sabina Rosas, an artist originally from Tajikistan, were in a “domestic” relationship, but did not provide additional details.

It’s unclear what the pair were doing at the $1,000-per-night spa where Rosas’ body was found by an employee on Monday, sending shock waves around Water Mill, a posh hamlet in the Town of Southampton on Long Island.

Rosas’ family described her in a statement as a “beloved daughter, sister, fiancee and friend,” and it is believed she was engaged to a different man, according to sources.

“As the eldest of three daughters, Sabina brought excitement, adventure, joy and love to our family,” the family said.

“Your support during this challenging time is a testament to just how special Sabina was and will remain.”

Gannon, a father of one, was the owner of Majestic Tile, Granite and Flooring in Honesdale, according to records.

His ex-wife did not immediately return The Post’s request for comment.

The home where he was found is listed for sale for $550,000, the online listing showed.

The three-bedroom, three-bathroom house is perched on an elevated deck with large windows offering stunning views of the surrounding woods.

The three-acre lot includes a pool and a private stream, according to the listing.

Rosas was found dead by a staff member in one of the 13 guest accommodations at the swanky Shou Sugi Ban House in Water Mill on Monday afternoon.

While the details of Rosas’ death were not immediately clear, it was believed to have been a very bloody, violent scene, according to reports.

Earlier Wednesday, ABC News reported that law enforcement was seeking a male suspect who checked into the spa with Rosas and was last seen leaving without her Monday morning.

The brutal killing cast a dark cloud over Water Mill, a serene, well-heeled enclave favored by celebrities and high-net-worth vacationers.

The Shou Sugi Ban House — which is tucked away at the top of a long gravel driveway off the Montauk Highway — has catered to famous clients including Kate Hudson and Katie Couric.

The incongruous site of police tape around the Buddha statue that marks the spa’s entrance set local tongues wagging about the shocking crime. 

“It’s just so uncharacteristic of this area, and that area in particular,” resident Jean Wong told The Post.

“It’s very ironic, because you go to a place like that for relaxation and comfort. What could have brought on a murder?”

Rosas — who also sometimes used the surname Khorramdel — appeared to live somewhat of a nomadic life, according to her online presence.

She was part of the nonprofit Harvestworks’ 2021 Technology Immersion Program and had been crowdsourcing cash to attend an artist residency in Portugal next month, a GoFundMe page shows.

She was also the founder of Ruyò Journal, a publication highlighting Central Asian art.

Rosas recently traveled with Ruyò to Tajikistan to Kyrgyzstan, where she exhibited a “multisensory experience” installation called Seed Forms, the journal said.

“Driven by her incredible energy and vision, Sabina moved walls so that gardens could flourish, inviting everyone seeking light. She shared everything she had and supported all of us,” Ruyò posted in a tribute to the late creator.

“A beautiful soul and a gifted artist, she left an impactful legacy in the arts of Central Asia. The world feels empty without her.”