ST. PETERSBURG, Fla. (AP) -- A woman and her roommate were charged with starving the woman's 9-year-old daughter, who weighed just 42 pounds when she was found, was locked up all day and was forced to wear a filthy diaper, authorities said.

Melissa Samoraj, 27, and Raymond LaFountain, 31, were arrested Wednesday and charged with aggravated child abuse. The girl was so emaciated that her spine and ribcage were showing when state child welfare officials took her June 30, police said.The girl also had her hands bound behind her, was locked in a bedroom all day and wore a diaper that went unchanged for hours, officials said. She told police it was punishment for bad behavior.

"It's a very disturbing case," police Detective Joe DeLuca said. "You see very few like this."

The girl now lives with her grandparents and has gained about 25 pounds in a month.

"She's doing well now," DeLuca said.

LaFountain's mother reported the girl's appearance after visiting the home, DeLuca said. It's not clear how long the alleged abuse had been going on, police said.

Samoraj and LaFountain were in a Pinellas County jail Thursday, each held on a $50,000 bond. DeLuca said they did not address the allegations when they were arrested Wednesday, and jail records did not indicate if they had lawyers.

LaFountain was originally described by police as Samoraj's live-in boyfriend, but the gender classification at the jail was changed from male to female following a routine strip search, Pinellas sheriff's spokesman Mac McMullen said.