New York (CNN) -- The New York Police Department has identified the father of "Baby Hope" and want to speak with him as part of their 22-year investigation into the girl's death.
Police stopped short of calling the man a suspect.
"He is someone we definitely have to talk to," NYPD Assistant Chief Joe Reznick told CNN on Thursday, "But can we arrest him for this right now? The answer is no, definitely not."
Investigators are looking for the father and believe he is in New York City.
"We're very interested in him," a law enforcement official told CNN.
"Baby Hope," a little girl whose body was found in a blue and white picnic cooler in a wooded area near the Henry Hudson Parkway on July 23, 1991, was never identified until this week.
Police now believe "Baby Hope" was South American, according to Reznick.
Reznick is "confident" an arrest will be made in this case, but could not state when that might happen.
"Trust me when I say the investigation is probably more active now than it's ever been during the course of 22 years," Reznick said.
As CNN previously reported, police have identified the little girl and her mother but will not make either name public because of the ongoing investigation.
The girl, then believed to be 3 to 5 years old, was smothered and sexually molested. Her body was so badly decomposed that several sketches were made to suggest what she looked like.
Thanks to a tip, the department confirmed the identity of the girl's mother through DNA testing, according to Police Commissioner Ray Kelly. The body was exhumed in 2011.
"A DNA match was made with the mother and the mother has been cooperating," Kelly told reporters Tuesday. He declined to name the mother or provide details on the case.
"Homicide is a distinct possibility here, so it's going to go forward in that direction," Kelly said of the investigation.
The girl was never reported missing and police could not track down anyone who might have known her.
The NYPD Cold Case Apprehension Squad never gave up hope, continuing to hand out flyers and canvas nearby neighborhoods every year on the anniversary of the discovery of the body.
"We have been able to identify the mother of Baby Hope as a result of, in my judgment, outstanding detective work," Kelly said on Tuesday.
Detective Robert Dewhurst, a member of the squad, told CNN in July that several detectives were still on the case and that people with information may speak many years later for many reasons, such as feeling safer after moving to a new area where they don't see the person responsible every day.
Sometimes people "want to get it off their chest," said Dewhurst.
For months after Baby Hope's body was found, police went back to the site hoping whoever was responsible, driven by guilt, had left some type of memorial that would have helped police.
Baby Hope, two years after she was found, was laid to rest in a donated plot. She was buried in a white dress bought by a detective's wife.
CNN's Rande Iaboni and Chris Welch contributed to this report.