The estranged husband of the Queens mom suspected of savagely beating their twin toddlers — one fatally — flung himself to his death from the top of a Midtown hotel, where his twisted body was discovered on Saturday, police sources told The Post.

Mohammad Torabi, 31, was found at 1:20 p.m., sprawled atop a third-floor air-conditioning unit at the Renaissance New York Hotel on East 57th Street.

Police believe he plunged from the roof of the 17-story hotel sometime Friday and had been dead for a day before he was spotted.

The unemployed Manhattan man left behind no note, but police say they are investigating the death as a suicide.

News of Torabi’s death came as his wife, Tina, 30, sat in Rikers for the near-fatal beating of their 13-month-old son, Kian — and as coroners prepared an autopsy report on his twin sister, Elaina, who was found dying in the family’s Flushing home on Wednesday night.

Both twins suffered “severe body trauma,” police have said.

By Saturday night, the mom remained charged only with “depraved indifference” assault, alleging that her reckless conduct created a grave risk of Kian’s death.

The charge does not specify if she allegedly beat him; she is also not charged in the girl’s death.

She has remained mum to cops.

Meanwhile, police sources revealed investigators had been looking to question the father, who had a history of drug abuse and domestic violence against the mother.

He was convicted in Texas of misdemeanor and felony assaults against family members in 2015, records show.

“Maybe he’s the one who did all that stuff to his daughter,” one investigative source speculated. “He must have thought, ‘I’m going to jail now.’”

The husband’s death-plunge ended a troubled marriage marred by drugs and violence.

Mohammad and Tina, a pharmacy technician, married in Houston in 2012 and lived in Texas before moving to New York to be near his relatives. Sources familiar with the case have said Mohammad at some point turned his wife on to drugs.

The twins were on the city’s radar since they were born last year with opioids in their systems.

Tina won an order of protection against Mohammed last January. It has been repeatedly renewed and ran through Oct. 10, one city source has said.

“We knew the dad was no good and didn’t want him anywhere near the wife and kids,” the source said.

Still, the father was occasionally seen with his wife and kids, said workers at a convenience store and a CVS near the basement apartment where the family lived since March. Raising five children alone took a toll on Tina, neighbors said. In addition to the year-old twins, there were three older children, sisters Mila, 2, Nadia, 4, and Ariana, 5.

“I’ve seen her taking the kids to school,” to drop Ariana off at nearby PS 107, said one neighbor.

“She would have all five of them. The twins were in her arms,” the neighbor said. “She never looked like something was wrong with her, she [just] looked overwhelmed.”

Workers at the CVS remembered the kids as sweet, but “dirty” and “running amok.”

“She would always smell like urine,” a cashier who asked not to be named said of 2-year-old Mila.

“They would, like, play hide and seek and stuff,” she said of the children. “I would say, ‘Your mom is coming,’ and she [the mother] would just stand there.”

The mom always looked tired.

“Most of the time she was so overwhelmed because there were so many kids,” the cashier said.

Still, even at the precinct station house after her daughter’s death, Tina “was well-dressed, well-spoken — you wouldn’t expect that from her,” one law-enforcement source told The Post.

“I cannot believe, I cannot believe what I saw, what I hear,” said Reza Razavi, an in-law of Mohammed and the owner of the home where the mother and five children had lived in the 800-square-foot basement since March.

“I wish it was all dreams,” he added.

Razavi, who lives in Nashville, happened to be visiting the house Wednesday.

That night, “I heard Tina yelling that the kid is not breathing. The first thing I did, I called 911,” he said.

“I didn’t go to look,” he added, “because every second counts.”

Of Mohammed’s apparent suicide, he said, “If he did this, either he has to go to jail or he better kill himself. Because how could he live with torturing two small kids?”

Kian remained Saturday in critical but stable condition in the intensive care unit at Cohen Children’s Medical Center.

He suffered multiple broken ribs, bruises to his groin, a broken hip, a lacerated liver and severe swelling to his abdomen.

More lacerations were found all over his body.

The older children were inside the Torabi’s Ashby Avenue basement apartment when the 911 call was made on Wednesday night.

Arriving cops found both of the one-year-old twins near death.

Elaina was rushed unconscious to Flushing Hospital, but was quickly pronounced dead. She suffered bruising to the back of her head and genitals, a large wound on her abdomen and open lesions all over her body.

The three older sisters were unharmed, except for a small burn on Mila’s right ankle, sources said.

The three are now in the custody of the city’s Administration for Children’s Services.

ACS had visited the family’s home just two days before the mother’s 911 call, in follow up to a court ordered check, in part on whether the mother was completing substance-abuse treatment.

But the visit revealed “no red flags or physical signs of abuse,” an agency source has said.