After skeletal remains of an 8-year-old boy were discovered Sunday inside a Houston apartment, a woman and her boyfriend were arrested Tuesday.

The woman, Gloria Williams, is the boy's mother, and was charged with tampering with a human corpse and injury to a child by omission while her beau, Brian Coulter, was charged with murder, reported Fox News.

After an initial round of questioning, the two were released, but additional charges are expected, said Harris County Sheriff Ed Gonzalez.

Led by the Harris County Sheriff’s Office’s homicide, child abuse and crime scene units, the investigation is still not closed.

Inside the apartment in western Harris County near Houston, three boys aged 15, 10 and 7 were found abandoned along with the dead child. According to the county medical examiner’s office, the deceased suffered several blunt-force injuries.

The 15-year-old boy called for help Sunday afternoon and said that his brother had been dead for about a year, with his body rotting in a room right next to his, said authorities. Their parents had moved out months ago, leaving the children alone, said the teenager.

Gonzalez said that the boys were without supervision for "an extended period of time," but did not specify the duration. According to him, it looked like they had some food available during that time but when they were found, the two younger surviving boys seemed to be malnourished and had signs of physical harm.

Some of the residents of the apartment complex helped provide food to them, said a neighbor. But most of the residents did not seem to notice the boys nor the smell that came from the body of the dead child. However, one neighbor said that the odor was so foul that they couldn’t open the air-conditioner in their area.

Latin Times recently reported that Craig Eichhorn from the Alief Independent School District was asked whether the kids were registered to or studying at a school, he said that the identities of the kids were not revealed by the cops at the time. Eichhorn added that out of 41,000 students, they couldn't guess who they might have been. He shared that he had walked that complex every now and then, but it is huge, so the chances were that there were several hundred students there.

Child Protective Services was seeking emergency custody of the surviving boys.

A police officer has been accused of killing a 6-year-old boy after the child repeatedly asked him money to buy food in Datia district, Madhya Pradesh, India. This is a representational image. Pixabay