HOUSTON -- Two Houston parents have admitted to using cocaine after four of eight children tested positive for the illegal drug, officials told KPRC Local 2 Friday.

Houston police said they were concerned about the conditions in the family's northwest Houston apartment. A Child Protective Services spokeswoman said the couple, eight children and an invalid grandmother lived together in the one-bedroom apartment.

"There were concerns about the sanitary conditions of the home. There were roaches, ants," CPS spokeswoman Estella Olguin said.

Police filed a report with the state on Oct. 7. CPS officials said they did not know where the family was until Oct. 16, when an 11-month-old boy was brought to Texas Children's Hospital with a broken wrist and arm. His brain was bleeding. His parents claimed he had fallen off of a bed.

Olguin said, "He's got subdurral hematoma, which is more consistent with blunt trauma to the head, and he's got those two fractures, which is also consistent with something, some sort of trauma -- and non-accidental."

She said the boy did not appear to be in pain even though he had broken bones. Blood work showed that he and three of his siblings had cocaine in their bodies.

Tammy Lynn Melton and Emanuel Jones have been charged with injury to a child.

A neighbor said she hopes the family gets the help it needs.

"Their skin is white and you can just see dirt standing on their skin," said Diane Allen.

Allen said she and other neighbors tried to help the children and their mother.

"I used to tell her all the time, them little kids, they supposed to be clean. You're the one who supposed to be dirty. Now those kids will be clean," she said.

Investigators said they do not know how cocaine got into the children's bodies. They have been placed in state custody.