Arizona couple 'held three sisters captive' in home

Girls were held in alarmed rooms and had not bathed for up to six months

Photographs provided by the Tucson Police Department show Fernando Richter and his wife Sophia Richter who have been charged with the imprisonment of her three daughters in Tucson, Arizona (EPA/TUCSON POLICE DEPARTMENT)

Three sisters have escaped from a house in Arizona where they were allegedly held captive by their mother and stepfather for two years in filthy, elaborately alarmed and soundproofed rooms.

Two of the younger siblings, aged 12 and 13, had managed to climb through a window and run to a neighbour's house on Tuesday. They claimed their stepfather had kicked in their bedroom door and threatened them with a knife.

Police officers then searched the property and found a 17-year-old girl locked in her bedroom.

In a news conference, Tucson Police Chief Roberto Villasenor said the girls were malnourished and dirty, and told police they had not bathed for up to six months.

The house in which the girls were held had been fitted with round-the-clock video security, he said.

The house the girls were allegedly held captive in by their mother and stepfather (AP)

"Their movements were controlled - when, where and how they went to the bathroom, when they were fed."

Tucson police captain Mike Gilooly told reporters: "They were kept in filthy living conditions separately and told patrol officers that they had not seen each other in almost two years."

Villasenor said loud music was constantly played in their bedrooms to conceal any noise they made, and towels were stuffed into ducts and around doors. If the girls were well behaved, the music would be replaced by loud static.

The girls' mother had a cell phone with a San Diego telephone number to convince their biological fathers and grandmothers that the family was living in California.

Investigators are now examining a journal kept by the eldest sister, detailing more than 18 months of captivity and abuse.

Villasenor said the teenager kept the diary in a satchel with a photo of singer Enrique Iglesias throughout her ordeal. She was overjoyed when the photo was returned on Wednesday, which she said was her most prized possession, after police examined the contents of her bag.

The girls have been evaluated by doctors and placed under the care of Child Protective Services.

Stepfather Fernando Richter, 34, and mother, Sophia Richter, 32, were charged with emotional and physical child abuse and kidnapping. The stepfather is also charged with one count of sexual abuse of a child under 15.

The couple have been together for about 10 years and married for three or four years, and there is evidence the girls were held against their will in at least one of the family's former homes, Villasenor said.

They made a brief appearance in court on Wednesday. Both parents did not enter a plea.

Additional reporting by Reuters