NEWARK, N.J. — When federal prosecutors investigating Sen. Robert Menendez brought a Ukrainian model before a grand jury in 2013, they bluntly pressed her about her relationship with a donor accused of bribing the senator.

"You became intimate with Dr. Melgen, correct?" a prosecutor asked Svitlana Buchyk, who the government says obtained a visa to the U.S. with Menendez's help.

"For one month," she said, according to court records.

"Is that a yes?" the prosecutor continued. "For one month, yes," Buchyk replied.

But when Buchyk took the witness stand during the trial last week, prosecutors didn't ask about any affair with Salomon Melgen, a Florida eye doctor and Menendez's codefendant. Under questioning by prosecutor Peter Koski, Buchyk described Melgen as a "family friend." Koski didn't ask her to elaborate.

Her testimony came days after U.S. District Judge William H. Walls scolded prosecutors for their "tabloid" line of inquiry and said he wouldn't allow it to continue. The contrast between the model's grand jury and trial testimony underscores how a salacious case rooted in disproven allegations that Menendez engaged in overseas trysts with underage prostitutes has been sanitized in federal court here.

This week, the senator's lawyers scored a win when the judge allowed them to introduce evidence suggesting that actions he took on Melgen's behalf were no different than constituent service he had performed for others.

The first three weeks of the much-hyped trial — the first of a sitting U.S. senator since Alaska's Ted Stevens in 2008 — promised a glimpse into the secret world of favors and luxury shared by a powerful legislator and one of his most generous donors and friends.

Before breaking for the week early Wednesday afternoon, prosecutors had called about 20 witnesses. But much of their testimony was a tedious slog through detailed flight records, emails, and other documents. On Wednesday, for instance, jurors spent more than an hour considering federal ethics disclosure forms.

That is due to the octogenarian judge who has commanded the courtroom here in Newark, offering comedic relief with allegories and references to movies while also reining in prosecutors and defense attorneys, interrupting the proceedings to lecture about the rules of evidence.

The start-and-stop pace has helped push the trial's timetable to Thanksgiving, meaning it's almost certain that Democrats in Washington, desperately needing every vote to counter the GOP controlled Congress and White House, won't have to worry about losing a senator to expulsion this year.

For his part, Menendez, after his tearful insistence on the trial's first day that he would be vindicated — that Melgen was nothing more than a good friend — has been silent at the defense table, showing little reaction and letting his lawyers spar with prosecutors and the judge.

On the first day of witness testimony Sept. 7, prosecutor J.P. Cooney suggested Menendez had traveled to Paris so he could sleep with a woman, prompting the judge to dismiss the jury temporarily and lambaste the attorney's bad "pulp-fiction story."

"What is interesting to me, more than anything else, is the government didn't adjust as a result of the court's ruling or at least consider the court could rule like that," said Lee Vartan, a former federal prosecutor, referring to the judge's admonition against lurid lines of inquiry.

Whereas the senator's assistance in visa proceedings seems like "mundane" constituent service, Vartan said, his lobbying the secretary of Health and Human Services on the doctor's behalf "would be more jarring" to the jury. "These women were never going to be friendly to the government," Vartan said. "And in fact they weren't."

(Asked by a defense attorney how much time she spent with the government preparing for trial, Buchyk said to laughter in the courtroom, "It just seems very long when I'm around them, but it's very, very long.")

Walls' prohibiting of a "tabloid" trial could help Menendez – but is not a silver bullet, observers say.

"Tactically the defense will have less ground to cover," said Mark Lee, a former federal prosecutor who's now a criminal-defense attorney with Blank Rome LLP in Philadelphia.

Bribery cases often feature tales of lavish spending and prurient activities, and judges try to make sure that "prosecutors don't necessarily go across a line where a defendant could be unnecessarily tainted," said Jeff Cramer, a former federal prosecutor in Chicago and now managing director of Berkeley Research Group.

But, he added, "That's not going to make or break the government's case." Showing jurors evidence of the opulent lifestyle Menendez led via Melgen's largesse could help prove they had criminal intent — and undercut the defendants' friendship defense.

The government accuses Menendez, a New Jersey Democrat, of using the power of his office to advance Melgen's personal and financial interests, including by lobbying high-level government officials over the doctor's $8.9 million overbilling dispute with Medicare. Menendez also took action to try to protect Melgen's multi-million dollar port contract with the Dominican Republic, prosecutors say.

Melgen kept Menendez on retainer with gifts and hundreds of thousands of dollars in campaign contributions, prosecutors say. They accuse Menendez of covering up the scheme by omitting the gifts from his financial disclosure forms.

The senator argues that prosecutors have mistaken his friendship with Melgen for a crime.

Menendez's defense has long maintained that prosecutors have been obsessed with baseless allegations of sexual misconduct that the senator says tainted the investigation.

Even after escorts recanted their claims and said they had been paid to make the allegations against Menendez, during grand jury proceedings the government "relied heavily on particularly salacious and inflammatory lines of questioning in an effort to prejudice the grand jury against Senator Menendez and Dr. Melgen," defense attorneys wrote in a pretrial motion.

For example, Buchyk, the Ukrainian model, was asked before the grand jury whether Melgen paid for her apartment in New York. (He did.) Prosecutors asked another witness about Melgen's extramarital affairs.

Prosecutors argued in response to the motion that "part of the corrupt exchange" involved Menendez using his Senate office to help Melgen "bring his foreign girlfriends into the United States, while defendant Melgen used his wealth to help defendant Menendez take his American girlfriends on exotic overseas vacations."

Now at trial, though, the government has scrubbed any hint of raciness from its playbook.

To be sure, jurors have seen photos of the amenities that were available to Menendez during his trips to Melgen's villa in a gated 7,000-acre resort in the Dominican Republic: the No. 44-ranked golf course in the world, overlooking the Caribbean Ocean; a marina; and beaches. There was no evidence that Menendez actually used them .

But when a prosecutor on Monday asked the president of the Casa de Campo resort what kind of services were provided by the spa, Menendez's attorney Abbe Lowell objected.

"Are we going to find out how much it costs to take a massage that he never took?" Lowell asked.

"No," the judge said, "we're not."

Then the prosecutor moved on to photos of world-class golf courses.