MANHATTAN — The NYPD has cracked one of the city’s most notorious cold-case murders — the killing of a child known only as “Baby Hope” whose body was found stuffed in a cooler 22 years ago, DNAinfo New York has learned.

Sources say detectives have located Baby Hope’s mother in Washington Heights and have confirmed her biological link to the slain 4-year-old girl through a DNA match.

The NYPD has now turned its focus on finding Baby Hope’s father who, sources say, ran off with the little girl and her older sister just months before Baby Hope’s body was found on July 23, 1991, according to the mother’s account.

The man, whose name is being withheld, is being sought as a person of interest in the girl’s death.

The break in the decades-old mystery unfolded last week when DNAinfo New York learned about the dramatic development.

A tipster — herself a mother in Washington Heights — reached out to the police and reported that she might know the identity and whereabouts of Baby Hope’s mother.

She told investigators that she was washing her clothing in a local laundry a couple of years ago and overheard a woman talking about the Baby Hope case and saying she believed she was the dead child’s mother.

The tipster did not think to call police at the time, but said she was prompted to come forward when she saw recent news reports about the 22nd anniversary of the killing.

Over the years, two generations of detectives had followed scores of false leads about Baby Hope, only to wind up in dead ends. The plight of one lead detective was detailed in a recent “On The Inside” column.

Despite understandable skepticism, several cold-case detectives tracked down the laundry woman — and this time they hit pay dirt.

The woman, whose name is being withheld, is of Mexican descent.

She provided a DNA sample for police and then spent two days late last week unburdening herself to detectives and prosecutors from the Manhattan District Attorney's office with a gut-wrenching and bizarre tale of guilt, torment and fear.

Frequently breaking down in tears, she said she had two daughters and had been married to a brutish husband who vanished early in 1991 — taking both her children with him.

She insisted she wanted to go to the police, but was terrified of what her husband might do to her or, worse still, her girls, if he found out. She hoped they would return unharmed.

Instead, she said, her worst nightmare became reality.

On July 23, 1991, the body of a girl, approximately her younger daughter’s age, was discovered in Inwood Park.

Parkway construction workers stumbled upon a cooler in a bucolic section along the Henry Hudson Parkway. When they pushed it over, a mixture of water and Coca-Cola spilled out.

They were also hit with the unmistakable odor of a decomposed body that turned out to be that of a badly malnourished girl, virtually a skeleton, weighing 28 pounds. She was hog-tied, naked and wrapped in a plastic bag.

Detectives theorized that whoever killed her placed her body in the cooler and covered her with Coke cans and ice to mask their crime. The summer sun not only melted the ice but also popped the soda cans, which destroyed forensic evidence.

An autopsy later disclosed she had been smothered and was dead about a week. There were signs of sexual abuse but that was never proven by science. An anthropologist determined she was 4 years old.

Even in a city ravaged by crime with 2,000 murders a year, the grim find was front-page news.

The discovery sent chills through the mother, she told police, and only made her more fearful.

Detectives, meanwhile, believed there would be a quick resolution to the killing. After all, most child deaths involve a relative and the police expected someone to report the child missing and help crack the case.

The NYPD kept the child’s body in the city morgue for two years. Finally, cops decided it was time to organize a proper funeral and burial for the little girl. They had referred to her only as "the baby" before Sgt. Robert Maas came up with "Baby Hope."

On July 23, 1993, Baby Hope — wearing a communion dress provided by Catherine Giorgio, whose husband, Jerry, was among the first detectives to find her body — was placed in a tiny coffin.

Roughly 500 mourners, most of them children and cops, packed St. Elizabeth’s Church on Wadsworth Avenue for her funeral before she was laid to rest in St. Raymond’s Cemetery in The Bronx.

Her black headstone was engraved with her moniker, the date she was found, and the words, “Because We Care.”

The detectives held out hope they would eventually get a break. Some even returned to the grave on the anniversary to pay their respects and hoped to find a clue from a guilt-ridden relative.

But they remained in the dark about another development, Baby Hope's mother told them.

About eight years after her children disappeared, the mother's eldest daughter — now a full–grown teenager — suddenly showed up at her mother’s door, she told detectives. The mother said she did not ask her eldest daughter what happened to her younger daughter, apparently because she already knew the truth and did not want to traumatize her surviving daughter and risk driving her away.

“She said they apparently never talked about it,” one law enforcement source said, explaining that detectives are trying to verify details of her account.

The sources did not say how Baby Hope's mother supported herself, or what her current relationship is with her surviving daughter. She went on to have children with at least one other man, sources said.

As of now, she is not considered a suspect in the child’s death and there are no immediate thoughts of bringing any charges against her, sources said.

“She is being treated as a victim,” one law enforcement source said.

The NYPD has instead turned its full attention to finding Baby Hope’s father. As of Monday, investigators continued scouring records to determine if he is dead or alive and, if so, where he might be.

Deputy Commissioner John McCarthy, the department's spokesman, said only that the case remains "under active investigation."