Story highlights The child had been in the apartment for five or six days, police said

There was food in the refrigerator, but the boy could not open the door

The decomposing body of a woman was found in a bedroom

Police would not say whether the woman was related to the child

A 4-year-old boy was found alive but malnourished in a Union, New Jersey, apartment where police also discovered the decomposing body of a woman.

Authorities revealed few details about the case, including whether the woman was the child's mother.

Late Tuesday morning, police responded to a call from maintenance staff at the Mill Run at Union Apartments in Union Township, about seven miles southwest of Newark. There were concerns about a foul odor coming from one of the apartment units, police said.

Officers discovered the door of that apartment ajar, but secured from the inside with a chain lock. Officers forced the door open and found a 4-year-old boy, according to a statement released by the Union Township Police Department.

Police Director Daniel Zieser told CNN affiliate WCBS that the boy had apparently been in the apartment for five or six days, with no food he could reach. Zieser said that the boy told a responding officer that there was plenty of food in the refrigerator, but that he couldn't open the door.

The boy "appeared very malnourished but alert," police said in a statement.

In the bedroom of the apartment, officers discovered the body of a woman "in a state of decomposition," the statement said.

The child apparently had been trying to take care of the woman, police said.

"He was...putting some type of lotion on her, but she was deceased. It's very sad," said Zieser.

Emergency services arrived at the scene and the child was taken to a nearby hospital for treatment.

The local medical examiner's office scheduled an autopsy on the body,though Zieser said the death appeared to be of natural causes.

CNN's attempts to reach the medical examiner were unsuccessful.

Management personnel for the apartment facility told CNN that they were not providing a statement Tuesday.

Efforts to reach family members of the boy were underway Tuesday, police said.