Three teenagers have escaped what they say was two years of captivity by their mother and stepfather, during which they were starved and not allowed to wash.
The Arizona sisters, aged 12, 13, and 17, were malnourished and filthy, and said they hadn't seen each other for nearly two years when they finally escaped on Tuesday (Wednesday NZT), US police said.
Tucson Police Captain Michael Gillooly said they told officers they hadn't taken a bath in up to six months.
"They were kept in filthy living conditions," said Gillooly, adding that the two youngest girls were kept in a separate bedroom from their 17-year-old sister.
The girls also told authorities that they were fed only once daily and had been imprisoned in their bedrooms for at least the past several months and possibly up to two years.
Sophia and Fernando Richter were arrested for the alleged imprisonment and made brief court appearances.
Both face multiple counts of kidnapping and child abuse, and he also faces one count of sexual abuse.
Police went to a midtown home on reports of a domestic violence incident, according to Gillooly.
The two youngest girls told officers that they ran to a neighbour's home after their stepfather kicked in the door and threatened them with a knife.
When officers went into the house, Gillooly said they found the oldest girl in another bedroom.
A woman who has lived in the nighbourhood for about five years told the Arizona Daily Star that she didn't know anyone was living in the home, which is set back from the street.
The woman said there was no visible activity at the house, but other neighbours had told her that they had heard what sounded like children playing inside the house at night.
The Star reported that police removed plastic bags containing evidence from the home and what appeared to be a computer.