A 10-year-old boy who weighed just 35 pounds when he knocked on a neighbor's door pleading for food was being treated Monday for malnutrition, while his mother was held on child neglect charges, police said.

The Port St. Lucie boy, whose name was not released, knocked a neighbor's door Saturday night pleading for food. The woman gave the boy a peanut butter sandwich and juice, then called authorities.

"He was extremely dirty, filthy, hair was matted. He looked like he was undernourished and extremely thin, and he was begging her for food," Officer Robert Vega said.

The average weight for a 10-year-old boy is about 85 pounds, according to the Centers for Disease Control and Prevention.

Kelleen Deon Murray-Auguste, 37, told authorities her son had been living with his father in Haiti until about a month ago, when the father dropped him off in Florida and left.

"She says he was brought to her home in that condition," Vega said.

The woman said she tried to feed him but he couldn't keep any food down. She did not seek medical treatment because she didn't have health insurance, Vega said.

Authorities were looking for the father, whose name was not released.

The woman has nine children ranging in age from 2 to 23 and is pregnant, Vega said. The Florida Department of Children & Families took custody of seven underage children ages 2 to 16, including the 10-year-old boy, he said.

He said none of the children except the 10-year-old showed signs of malnutrition and neglect.

The mother was being held Monday on $150,000 bail, said sheriff's spokesman Mark Weinberg. It was not clear whether a public defender had been assigned. A telephone listing for Murray-Auguste could not be located.

The child was in state care and being treated for malnutrition.

"He's doing better now. They're just trying to provide him the nutrients he's been lacking for so long," Vega said. "Who knows how long it could have been before he got the help he needed. I think he's pretty lucky."