Someone called police from the hotel to warn him that he might get behind the wheel, a source says

Someone at the fancy Hamptons hotel where Justin Timberlake was drinking cocktails before his drunken driving arrest called police because they were worried he was going to get behind the wheel, the owner of a local bar said.

“(They) said Justin had been drinking a lot and they told the cop to watch out for him if he wanted to drive,” the well-connected Southampton restaurant owner, who wished to remain anonymous, told The Post on Sunday.

To maintain anonymity, the local businessman did not say whether the caller was an employee or a guest of the American Hotel in Sag Harbor, nor whether he was part of Timberlake’s own party.

The 43-year-old superstar eventually hopped into his gray BMW 2025 after the party at the American Hotel in Sag Harbor – and was promptly stopped by a young police officer who gave him a warning, thinking that would be enough to keep him off the road, a source in local law enforcement previously told The Post.

But a few minutes later, the same officer spotted Timberlake still in the driver’s seat of the BMW, only this time the singer had allegedly missed a stop sign and veered off his lane. Reeking of alcohol and with bloodshot eyes, he failed several roadside breathalyzer tests and was arrested, police said.

Neither American, Sag Harbor police nor Timberlake’s press agent immediately responded to The Post’s questions on Sunday.

His attorney, Eddie Burke, said he had no comment at this time.

The restaurant source said they believe the “Cry Me a River” singer was “mistreated” in the embarrassing incident that made headlines around the world.

“(He was) definitely treated unfairly,” the source said.

“Everyone runs that stop sign when there’s no one there,” the source claimed, noting that Timberlake, a 10-time Grammy winner and married father of two young boys, was a “regular at the Hamptons” and had visited its eateries “many times” over the years.

“He was always a gentleman,” the restaurant owner said of the star. “People always recognize him and ask for a photo, and he always says yes. He has his hat pulled down low over his face and is wearing sunglasses, so it’s hard to recognize him, but some people do.

“He’s not like Leonardo (DiCaprio). Leo doesn’t like being recognized and he even swears. He doesn’t take photos, especially when he’s with a group of models,” the source said.

The restaurant owner said he also doesn’t believe the widely circulated claim that the young police officer who stopped Timberlake – a young Sag Harbor police officer named Michael Arkinson – didn’t recognize him.

“If you live in America, you know who Justin Timberlake is,” the source said.

“The cop was doing his job, but he definitely knew who Justin was.”

But another local businessman, 54-year-old Mark Zucchero, owner of Flying Point Surf and Sport, said he believes Arkinson.

“(The cop is) definitely not a bad guy. He’s hardworking, he does a good job. He just didn’t know who Justin Timberlake was! That’s all, simple as that.”

Kirk Severance, 31, who runs the True Value Hardware emporium directly across from the American Hotel, added: “The police here are pretty lenient and understanding.

“All nice people. Some of them come here. In the winter they are really relaxed, but in the summer they can be a bit strict because of the crowds,” said the local.

On Sunday, two cars were parked in the driveway of Arkinson’s Hamptons home and people could be seen inside, but no one came to the door when The Post reached out for comment. Police officers later warned postal workers to stay away.

Timberlake told arresting officers that he had only had one drink, a martini, but he still refused to take a breathalyzer test three times, according to court documents.

The former “Mickey Mouse Club” member made his first public statement since his arrest on Friday evening on stage at the United Center in Chicago.

“It’s been a tough week,” the “SexyBack” singer told the crowd.

“I know it’s hard to love me sometimes, but you always love me too,” the former NSYNC member continued from the stage as the audience showered him with cheers.

Timberlake continues his “Forget Tomorrow” world tour with a two-night performance at Madison Square Garden on June 25.