A small private plane carrying three people crashed into the Atlantic off the Hamptons Saturday morning — and the body of the male pilot had been recovered by nightfall, officials said.

The seven-seat, twin-engine Piper PA-34 went down about a mile off Quogue at about 11 a.m., according to a Coast Guard spokesman.

The plane lost radio contact with air-traffic controllers some time prior to the crash, law-enforcement sources told The Post.

The bodies of the two passengers, a man and a woman, remained inside the wreckage Saturday night, submerged in about 60 feet of water, the sources said.

The plane had been flying from Danbury, Conn., to Charleston, SC, officials said.

Surfers alerted authorities after seeing the aircraft — flying in light rain and winds — break apart and plummet, Coast Guard officials said.

The crash occurred about a mile east of Rogers Beach and about three miles southeast of Francis S. Gabreski Airport in Westhampton Beach, according to the FAA and police officials.

Tim Carbone, manager of the Surf Club in Quogue, recalled hearing a high-pitched revving sound moments before the plane went down.

“I was loading up my truck and I heard this high, high revolution,” Carbone told The Post.

“The engine was going way too fast. I thought to myself ‘Geez, that’s not good.’ ”

“I immediately thought it was a stunt [pilot],” he said. “But I’m thinking what are they doing out there today. It was cloudy and misting.”

Stunt pilots often practice over the ocean.

“Next thing I know, [the engine] just stopped. It was a muffled stop — it stopped in a second or two. I ran over to look and I saw three pieces of the plane floating down. They were falling down like leaves.

“I’m thinking ‘Holy Jesus, look at that!’ ”

Carbone saw his surfing buddy down the beach and ran over to him. The friend was already on the phone with cops.

Once the pieces dropped into the water, they quickly sank.

“We saw parts of the plane floating, but then they disappeared. It’s sad, it’s tragic,” Carbone added. “I feel bad for the families.”

Emergency personnel respond­ed to a debris field and oil sheen on the water, the Coast Guard said.

Multiple agencies joined in the rescue effort, including local police departments, the Air National Guard, the state Department of Environmental Conservation’s Marine Resources Division and the Coast Guard, which in its search employed a 45-foot boat along with 87- and 110-foot cutters.

By Saturday evening, authorities had not yet released the names of the victims.

The plane is registered to the Oxford Flight Training school at Waterbury-Oxford Airport in Connecticut, according to data provided by the sources.

It was manufactured in 1975, Federal Aviation Administration records say.

In June, a small plane with four people aboard plummeted into the Atlantic about a mile off of Indian Wells Beach in Amagansett.

“Builder to the Stars” Ben Krupinski and his wife Bonnie Bistrian Krupinski, both 70; their 22-year-old grandson, Will Maerov; along with pilot Jon Dollard, 47, were killed in the crash.