The gifts were lavish — Super Bowl tickets and vacations to China and London.

The favors were troubling — using NYPD cops to provide security for private cash and jewelry deliveries and police escorts for funerals and airport trips to transfer bodies to Israel.

New details emerged Tuesday in the FBI’s corruption investigation into the police department, including how deep-pocketed businessmen who were the original targets of the probe sought out high-ranking members who they knew could “get things done for them,” sources told The Post.

“They don’t go to police officers or detectives. They’re too far down the food chain,’’ a law enforcement source said of the politically connected businessmen.

“They go straight to the top: the [commanding officer], lieutenants and other top officials at the precinct,” the source added. “They get things done for them. All they need to do is make a call.”

The favors ranged from getting police escorts for their own business deliveries, to crowd control during Hasidic weddings, and even receiving special security when Torahs are moved, according to sources.

‘They don’t go to police officers or detectives. They’re too far down the food chain.’ - Sources to The Post

The feds are looking into whether high-ranking NYPD officers then received gifts as part of an illegal quid pro quo — including jaunts to the Super Bowl, China, London, Brazil and Rome, and golfing trips to the Dominican Republic, sources said.

The suspected corruption surfaced during a separate financial investigation into Mayor Bill de Blasio cronies Jona Rechnitz, an Upper West Side real estate powerhouse, and Jeremy Reichberg, a prominent figure in Borough Park, Brooklyn, the sources said.

Wiretaps on the two men raised red flags because there were so many phone calls to and from cops, sources said.

“When it’s replayed, it might not sound good,’’ a source said of the wiretaps, explaining that they involve one of the businessmen making requests and the cops saying they’ll take care of it, although it’s unclear if any criminal conduct occurred.

Up to 20 NYPD members — including Deputy Inspector James Grant, the head of the Upper East Side’s 19th Precinct, and two other deputy inspectors — are being grilled over what they might know, sources said.

Some were questioned during 5 a.m. visits to their homes by the FBI. Staten Island Highway Sgt. Al Bono was questioned by agents at his house last week.

Sources said the you-scratch-my-back-I’ll-scratch-yours arrangement between the department and local leaders has been going on for decades — and that Rechnitz and Reichberg are experts at mining it.

Rechnitz is “always bragging about his relationship with the cops, how he knows everyone,” a former work associate said.

Reichberg “likes to talk about himself and drop names of people he knows. He likes to brag,’’ a law enforcement source said.

“He drops names to the cops that he knows Mayor de Blasio and [former NYPD Chief of Department Philip] Banks. He thinks he’s a big shot because of his so-called connections,” the source added. “I don’t know why these [cops] got friendly with him.’’

Banks and his buddy, corrections officers union chief Norman Seabrook, were the first law enforcement officials to come on the feds’ radar, sources said.

Both took overseas trips with Rechnitz and Reichberg, with Banks’ and Seabrook’s bills at least partly paid for by Rechnitz, according to sources.

Banks also was treated to two golf trips to the Dominican Republic, a government source said, and Reichnitz covered his hotel bill in Israel, where Banks posed in uniform at the Western Wall, even though he was on personal time.

Ben Brafman, Banks’ lawyer, said Tuesday, “It does not appear that Mr. Banks, either while employed by the New York City Police Department or after he retired, was involved in any intentional criminal conduct.”

A source said Seabrook is suspected of using Rechnitz’s JSR Capital LLC to invest union money without board approval.

Seabrook has denied any wrongdoing.

Police Commissioner Bill Bratton said Tuesday that the NYPD will “cooperate fully’’ with the FBI and called probes like this “the nature of the business.”

“We’ll just have to see where the investigation goes, and it’s something that, as you’d expect, we will participate in and kind of cooperate fully with,” the city’s top cop said.

“That’s all I’m able to say at this time,” he said. “On these investigations, we’re not able to comment on them, and that’s an agreement with the bureau.”

Detective Michael Milici was placed on modified duty after pleading the Fifth when questioned by a grand jury during the probe — a disciplinary move that Bratton said was “for the good of the department.”

Neither Rechnitz nor Reichberg responded to requests for comment.

Additional reporting by Aaron Short and Jennifer Gould Keil