Jeffrey Epstein maintained his financial empire — and his perverted sideline of preying on underage girls for sex — with the aid of an army of alleged enablers, many of whom he kept in one Upper East Side building and lavished with perks.

The convicted pedophile, 66, who died Saturday of an apparent suicide after being found unresponsive in his Manhattan prison cell, frequently took his assistants shopping to designer boutiques in Paris on his private jet.

He paid for unlimited salon services at tony Frederic Fekkai in Manhattan and gourmet take-out meals from Le Cirque.

One assistant received a Mercedes and a nanny for her newborn to make her commute easier.

A battalion of lawyers, pilots and models who worked for Epstein stayed at a doorman highrise in Manhattan — the epicenter of the Epstein empire — in apartments controlled by him and his real estate investor brother Mark, public records show.

Many of the units at 301 East 66th St. were owned by a New York shell company registered in Columbus, Ohio, the home base of Victoria’s Secret owner and Epstein’s billionaire benefactor Leslie Wexner, according to records.

The white-brick post-war building was also the gilded cage where the billionaire trapped and preyed on many of his under-aged victims — sometimes with the aid of his army of enablers.

Girls recruited as models from around the world were brought to the US and the building by MC2, a modeling company run by Epstein pal Jean-Luc Brunel. The company was financed by Epstein beginning in 2003, court papers show.

The girls passed through various apartments in the building where assistants arranged for their work visas, booked travel and modeling jobs. Some were also dispatched for other duties to Epstein’s nearby mansion on East 71st Street, court papers say.

Epstein “was the one who said who stays in what apartment,” said Maritza Vasquez, who worked as a bookkeeper for MC2, in a 2010 deposition made public last month.

“Epstein and Brunel would then obtain a visa for these girls, then would charge the underage girls rent,” court documents say.

According to a cache of more than 2,000 documents unsealed Friday in a defamation case against British socialite and former Epstein gal pal Ghislaine Maxwell, Brunel had more than catwalk appearances planned for some of the girls. He offered up girls as young as 16 for “massages” with Epstein that often wound up as sexual-abuse sessions, according to documents filed in the lawsuit.

In 2005, Brunel called Epstein and left a message that “he is sending him a 16-year-old Russian girl for purposes of sex,” the court papers say.

The message, filed as an exhibit in the case, was written on an office message pad, partly in code, and read: “He [Brunel] has a teacher for you to teach you how to speak Russian. She is 2×8 years old not blonde. Lessons are free and you can have your 1st today if you call.”

Another message from Brunel to Epstein discusses how he had sex with an 18-year-old who had also been with Epstein. “He just did a good one – 18 years – she spoke to me and said ‘I love Jeffrey,’” according to court papers.

Juan Alessi, a former house manager for Epstein, told the court that over a 10-year period, Maxwell brought more than 100 young women that she called “massage therapists” to Epstein’s home. He said that when he cleaned up after them, he found vibrators and sex toys on the massage table.

Virginia Roberts Giuffre, a self-described Epstein sex slave, who sued Maxwell and claims that she procured her for sex with Britain’s Prince Andrew, said she was also “forced” to have sex with Brunel as well as Harvard law professor Alan Dershowitz, “and many other powerful men, including numerous prominent American politicians, powerful business executives, foreign presidents, a well-known prime minister, and other world leaders,” the documents say.

Among the other girls in Epstein’s harem was Nada Marcinkova, who had been allegedly bought from her parents in Eastern Europe by Epstein when she was 15, according to one of Epstein’s alleged victims.

Marcinkova, who now goes by the name Nadia Marcinko, was one of Epstein’s alleged “sex slaves” and allegedly participated in trysts with underage girls, according to court papers.

Marcinko is now a commercial pilot, and registered her Delaware aviation company Aviloop in 2011 while she was living at the East 66th St. complex.

Another Epstein enabler, Sarah Kellen, allegedly kept lists of young women to recruit as “massage therapists” for her boss, according to court papers. Along with his other assistants, she booked travel for them, and Kellen was a frequent passenger on Epstein’s private jet, flight records show.

Many victims allegedly told police that they were taken to Epstein’s massage room at his Palm Beach mansion by a woman named Sarah. According to authorities, the court papers say, both Kellen and Maxwell warned the girls not to speak about their encounters with Epstein.

After her employment with Epstein came to an end, Kellen started an interior design company — SLK Designs — at the East 66th Street address. She has since married NASCAR driver Brian Vickers and briefly changed her name to Sarah Kensington.

Neither Kellen nor Marcinko has been charged with a crime and both invoked the Fifth Amendment when questioned by authorities about their dealings with Epstein in the defamation case against Maxwell.

In 2007, Epstein sought to protect his closest aides, including Maxwell, when he negotiated his non-prosecution agreement for himself and “potential co-conspirators.” The agreement ensured that none of the women who worked as his enablers would be criminally charged. The federal immunity was negotiated with former Miami federal prosecutor Alexander Acosta, who became President Trump’s Secretary of Labor. He recently resigned over the Epstein agreement.

Lesley Groff, another former assistant protected under the agreement, allegedly coordinated travel arrangements with young girls and scheduled massage sessions for her boss. Groff was paid $200,000 a year, received a Mercedes E320 and the services of a nanny after the birth of her child, the New York Times reported.

“Ms. Groff never knowingly booked travel for anyone under the age of 18, and had no knowledge of the alleged illegal activity whatsoever. She is shocked and deeply distraught by the accusations and revelations concerning her former employer,” said her lawyer, Michael Bachner.

“They are an extension of my brain,” Epstein told the Times in 2005 of his assistants. “Their intuition is something that I don’t have.”

In addition to his secretaries, Epstein worked with his longtime lawyer Darren Indyke, who occupied a two-bedroom apartment at the East 66th Street building between May 2000 and February 2009, public records show.

Indyke’s apartment was owned by Ossa Properties, a firm controlled by Mark Epstein.

From an eighth-floor apartment and an office on Madison Avenue, Indyke, 54, registered a dizzying number of limited liability companies that owned Epstein’s $77-million Upper East Side townhouse and a nearby property used by Maxwell, a daughter of press baron Robert Maxwell, and an alleged key recruiter of girls to feed Epstein’s seemingly insatiable sex drive.

With her connections to British royalty and New York society, Ghislaine was also an important companion. She was a former girlfriend who introduced Epstein at elite soirees in London and New York.

Maxwell was accused by three women of procuring girls to work as sex slaves for Epstein in court filings. Two of the women said both Maxwell and Epstein sexually assaulted them. She has not been charged with a crime, and has not been spotted in public since Epstein’s arrest last month. A source told The Post that Maxwell is cooperating with federal authorities.

Epstein was sentenced to 18 months after his attorneys secured a 2008 sweetheart deal in Florida to avoid federal charges that could have resulted in a possible life sentence. He was released on probation after 13 months, during which he was able to go on “work release” to his Palm Beach office for 12 hours a day, six days a week.

Epstein’s millions also gave him entree to important financial institutions. For years, he was the personal financial advisor to Wexner, whose L. Brands empire owns Victoria’s Secret and Bath & Body Works.

When JP Morgan Chase Bank wanted to get rid of him as a client after he pleaded guilty to soliciting a prostitute in 2008, Mary Erdoes, one of the bank’s high-level executives intervened to keep him on, the Times reported last week. JP Morgan denied the charge.

Multiple emails and calls to Maxwell’s lawyers were not returned. Mark Epstein, a Wexner spokesman, and Dershowitz refused comment when contacted by The Post. Brunel, Kellen, Marcinko and Indyke could not be reached for comment.

Epstein was arrested in New Jersey last month, and had pleaded not guilty to sex trafficking charges.