She claims she is the secret scion of a Manhattan financier — her Dalton and college tuition paid by a furtive father she never knew, while her single mother cashed his monthly checks like clockwork for 20 years.

Today she is a beautiful star of a television police procedural who has taken a leading role in a real-life legal drama over the late mogul’s $100 million fortune.

Marina Squerciati, 36, who plays cop Kim Burgess on NBC’s “Chicago P.D.,” has never spoken about her dad, because he swore for years to provide for her in his will, according to court papers.

But John R. Jakobson — who at age 25 in 1955 became one of the youngest people ever to buy a seat on the New York Stock Exchange — broke his pledge, the actress claims.

The price of keeping quiet for most of her life, Squerciati claims, was “extraordinary.”

She lost the chance to bond with Jakobson, who died in April 2017 of pneumonia at age 86, and she was denied “any relationship whatsoever with her half-siblings,” say documents filed in Manhattan Surrogate’s Court.

One of those possible siblings is also a TV actress: Maggie Wheeler, 59, who appeared in “Seinfeld” but is best known for her role on “Friends” as Chandler Bing’s irritating, nasal-voiced, on-again off-again girlfriend, Janice.

In a 2017 interview, Squerciati told EW, “I don’t have any siblings.”

About 6 million viewers tune in for “Chicago P.D.,” where Squerciati pals around with castmates Sophia Bush and Amy Morton, who arranged a baby shower for Squerciati when she was pregnant with her daughter. The girl was born last year, a month after Jakobson’s death.

Jakobson’s family, including his widow of 34 years, Park Avenue socialite and noted etiquette author Joan Jakobson, apparently never knew of Squerciati’s existence.

“I’m not aware of it at all,” Joan Jakobson told The Post, asking incredulously, “She said she was John’s daughter?”

She later added, “This has all hit me, like, I don’t know — a snowstorm.”

John Jakobson was apparently quite the ladies’ man.

He was first married to his college sweetheart, Museum of Modern Art trustee Barbara Jakobson, with whom he had three children, including Wheeler. One of the three children died. The couple divorced in the 1970s.

In 1979, while planning to marry Joan, the tall, bespectacled finance man met former Miss America Bess Myerson, a longtime confidante of then-Mayor Ed Koch and member of his administration, at a party.

Myerson and Jakobson launched a torrid, months-long affair before Jakobson broke things off, prompting an unhinged Myerson to inundate him, Joan and various female friends with clandestine, vulgar letters and repeated hangup phone calls. The NYPD investigated Myerson, but she was never charged.

The scary end to one relationship didn’t stop Jakobson from starting another, this time with Squerciati’s mother, Marie.

An academic who wrote for television in the late 1970s and early 1980s, as well as the Village Voice, Marie Squerciati also popped out quirky travel pieces for the New York Times in the years before she met Jakobson.

She also had no trouble in the romance department, a relative said.

“My sister is and was a very beautiful and talented woman,” sister Gloria Maloney said. “Guys were always beating down her door.”

But Marie Squerciati never spoke of Jakobson or the year-long relationship that resulted in their daughter’s August 1981 birth.

And Jakobson, who went on to marry Joan in 1983, never spoke to his family of his baby girl. In addition to Wheeler, Joan also gave birth to a son, Nicholas.

Court papers do not reveal the circumstances surrounding the romance, and family members on both sides refused to give details.

With help from his longtime personal secretary and the headmaster of one of New York’s most prestigious schools, Jakobson arranged to provide for his daughter, court papers revealed.

He paid Marie Squerciati $1,200 a month for more than 20 years, which she used to hire a nanny for Marina and pay for her rent-controlled Upper West Side pad.

Jakobson also spared no expense for Marina’s education, shelling out more than $175,000 for her to attend the upper-crust Dalton School through her senior year, then another $131,000 for her schooling, room and board at Northwestern University, where she graduated in 2003 with a bachelor’s degree in theater, according to a Surrogate Court filing.

Dear ol’ Dad made sure to send flowers and birthday gifts to his apparent love child, even investing in a play she appeared in.

He did this while keeping up the charade that he was planning to create a “substantial” trust for Marina, similar to what his other children would receive, according to court documents.

When Marina got engaged, Marie Squerciati asked Jakobson if he would send a gift.

He replied by reaffirming that the girl “would receive money under his will,” his daughter claims.

But that never happened.

Jakobson’s estate plans included money for his first and second wives, his three surviving children and his stepdaughter through Joan, as well as funds for a namesake foundation.

Lawyers for the Squerciatis reached out to the estate in September to ask if Marina was named a beneficiary, court papers show. It’s unclear how much money the actress is seeking.

Nicholas Jakobson, the executor of his father’s estate, “has devoted substantial time and . . . considerable legal expense in analyzing the claim,” according to a court filing by the estate, which slams Marina Squerciati’s allegations as having “no basis in fact or law.”

Squerciati’s bid to be included in her alleged father’s massive estate “amounts to nothing more than an avaricious attempt to enforce an alleged, vague oral promise made to [her] mother, rather than to herself, and which resulted in no legally recognizable injury to her,” Jakobson’s lawyers asserted.

Even if Marina Squerciati could prove Jakobson is her biological father, she has no written evidence of his promise to provide for her in his will, the lawyers argued.

She had “ample opportunity as an adult” to get Jakobson to put his commitment in writing, the financier’s lawyers claim.

Keeping the secret may have even been something Marina Squerciati herself wanted, say the lawyers, who offered her a paltry $50,000 settlement.

“She may have wished to avoid the opprobrium, which, although unfair and unjustified, is often cast upon nonmarital children,” the lawyers wrote.

“As a successful actor, [she] may have been especially sensitive to this given her public persona and position in popular culture.”

The Squerciatis did not respond to requests for comment.