The search for a missing 6-year-old Texas boy — whose mother believed he was possessed by a demon — has become a death investigation, cops announced Thursday.

Noel Rodriguez-Alvarez, who has special needs, was last seen in late October or early November shortly after his twin sisters were born, Everman Police Chief CW Spencer revealed during a press conference.

“Noel was described as appearing unhealthy and malnourished,” the chief stated.

“Leading up to the birth of the twins, [his mom] had made several statements about Noel referring to him as evil, possessed or having a demon in him. [She] believed that Noel was going to harm the newborn twins.”

Noel was one of ten children to mom Cindy Rodriquez-Singh, 37.

Three siblings lived with grandparents, while Noel and the others lived with their mother in squalor in a shed in Everman, a suburb of Fort Worth.

Arshdeep Singh, the boy’s stepfather, also lived in the filthy shack which police found had an altar to Santa Muerte, or Saint Death — a female cult figure denounced by the Catholic Church who is popular with drug cartel members.

Investigators came to the conclusion Noel is likely dead after disproving multiple lies regarding his whereabouts told by Rodriquez-Singh, the cops confirmed.

They included that the boy was in Mexico with his biological father and that he had been sold to a stranger at a local grocery store.

“Cindy was known by relatives to be abusive and neglectful to Noel,” Spencer explained.

“One relative witnessed Cindy strike Noel in the face with keys for drinking water.

“Witnesses additionally stated that food and water were often withheld from Noel because Cindy did not like changing Noel’s dirty diapers.”

Authorities previously disclosed Noel was born prematurely and had several physical disabilities and developmental disorders.

They also described his mother as having an “extensive criminal history” and explained she was the subject of a previous investigation by Child Protective Services.

Arrest warrants for abandoning or endangering a child, a second-degree felony in the Lone Star State, have been issued for Rodriguez-Singh and her husband.

However, the pair are believed to have fled to Singh’s home country of India before the warrants were issued.

“On Nov. 1, 2022, Cindy obtained passport photographs for all of the children living with her, expect for Noel,” the chief said, adding that she then applied for passports the next day.

The FBI and other federal agencies are working to extradite the couple back to the US.

Meanwhile, search teams continue to scour wooded areas in Everman for the boy’s remains.

On Monday, the community plans to hold a vigil for him.