Little Mikey Guzman lived in a Queens house of horrors where child welfare workers had found cuts, welts and bruises on some of his siblings, as well as signs of sexual abuse, before the 5-year-old was discovered dead, law enforcement sources told The Post on Tuesday.

The city Administration for Children’s Services had investigated the family 13 times, and substantiated abuse or neglect in eight instances, yet never took any of the six children away, the sources said.

“The problem with ACS is their motto is, ‘Keep the families together’ — they would have kept the Manson family together,” a disgusted source said.

“How many chances do you want to give these parents, especially when these kids are defenseless victims?

“They would be better off erring on the side of caution and taking the kids. You can always give the kids back. When they die, it is too late to take them.”

The city Department of Investigation announced Tuesday it is probing ACS’ handling of Michael “Mikey’’ Guzman’s case.

His death follows a slew of high-profile child abuse cases involving kids whose families had past involvement with the beleaguered agency.

“We are focused on the critical issues of whether there continue to be systemic and preventable problems at ACS that place children in danger and whether ACS has implemented necessary changes noted in DOI’s prior investigations,” DOI chief Mark Peters said in a statement.

Peters noted the recent abuse deaths of 6-year-old Zymere Perkins and 3-year-old Jaden Jordan.

“Reports on these children and at least five others are expected to be completed in the near future,” he said.

“These investigations will build on the findings we have already published regarding failures by ACS in its investigatory and foster care oversight; and will focus on the actions of ACS staff, what real-time actions they took in response, and persistent vulnerabilities within ACS that DOI’s investigations continue to expose.”

Mikey Guzman lived in Jamaica with his parents, Phyllis Reinoso, 29, and Michael Guzman, 34, and five siblings.

The 13 ACS cases opened against the family, and involving Mikey’s siblings — Jennifer Acevedo, 15, Jazabella Acevedo, 12, Maylee Acevedo, 11, Manny Prince, 9, and Mathias Guzman, 2 — occurred between October 2008 and January 2016.

Eight claims of abuse or neglect were ultimately substantiated, and in two of the cases, some of the older kids had visible signs of physical trauma, with cuts and bruises on their bodies, according to law enforcement sources.

There also was evidence that one of the girls had been sexually abused by a relative.

In addition, the parents were found at times to not be adequately feeding or clothing the kids and failing to properly supervise them.

Despite the many warning signs, Mikey, who suffered from epilepsy and frequent seizures, was never removed from the home, where he was found unresponsive in his bed Sunday.

His mom told cops she found her son unconscious at 4:15 p.m. with vomit coming out of his mouth, according to law enforcement sources.

Reinoso said she had left the home hours earlier with Mikey’s dad, at around midnight, and returned at about 2:30 a.m. Sunday, police sources said.

When she got back, she said, she noticed that her son was having trouble breathing — but he looked well and was able to walk to his bedroom to go to sleep, according to sources.

Reinoso said she was home with her son’s dad Sunday, but they didn’t check on Mikey until that afternoon because they figured he was sleeping.

One of Michael’s siblings told cops a different story, saying Jennifer carried him to bed around midnight while the parents were out.

The city Medical Examiner’s Office has yet to determine the cause of the boy’s death, saying it “remains under investigation.”

Reinoso and Guzman were questioned Monday at the 103rd Precinct stationhouse and released, at least for now, sources said.

State Sen. Tony Avella (D-Queens) blasted the city’s child welfare agency, saying it’s “unbelievable” that ACS didn’t consider removing the children from the home.

“It is shameful that we have to keep hearing of a child’s life being cut short due to a city agency’s negligence,” he said.

ACS did not respond to questions about the DOI investigation or whether it needed to rethink policies on how allegedly abused children are removed from homes.

“We may remove a child from their home when there is imminent danger, and [court] approval is always required,” the agency said in a statement. “Even in the instance of an emergency removal, utilized in our most egregious cases, Family Court approval is required within 24 hours.”

Additional reporting by Rich Calder