A US woman found after being abducted as a girl in 1991 gave birth to two children fathered by her alleged kidnapper - the first when she was 14.
Jaycee Lee Dugard and her daughters, 11 and 15, were kept in a "hidden backyard within a backyard", police say.
Alleged kidnapper Phillip Garrido, 58, and his wife Nancy Garrido, 54, are being held in custody in California.
DNA tests are being done to confirm Ms Dugard's identity, but meanwhile she has been reunited with her mother.
"She was in good health, but living in a backyard for the past 18 years does take its toll," El Dorado County Undersheriff Fred Kollar said.
Ms Dugard disappeared in 1991, aged 11, apparently taken by two people who bundled her into a car.
Mr Kollar said that since the kidnapping she had lived with the couple, isolated from view at a property in Antioch near San Francisco, 170 miles (273km) from her home in South Lake Tahoe.
"The tents and outbuildings in the backyard were placed in a strategic arrangement to inhibit outside viewing and to isolate the victims from outside contact."
She and the children spent "most of their lives" there, he said, adding that they had never been to school or seen a doctor.
Their identities were revealed after police spotted Mr Garrido as he handed out religious literature at the University of California Berkeley campus with the two young children.
He raised suspicions because as a registered sex offender he was not allowed to be with young children.
He was called in by his parole officer for questioning, and brought the two children and a young woman he called Allissa with him.
During questioning he revealed that Allissa was actually Ms Dugard. She also confirmed her identity to police.
In a telephone interview from prison with the KCRA-TV station, Mr Garrido said he had not admitted to abduction and that the birth of the first child 15 years ago had changed his life.
"If you take this a step at a time, you're going to fall over backward and in the end you're going to find the most powerful, heart-warming story," he said.
"I tell you here's the story of what took place at this house and you're going to be absolutely impressed.
"It's a disgusting thing that took place with me in the beginning. But I turned my life completely around," he said.
Some of those who had had contact with Mr Garrido over recent years said he had developed increasingly strong religious beliefs.
Tim Allen, who did business with Mr Garrido's printing firm, told Associated Press that Mr Garrido gave the impression he was planning to establish a church. "He rambled. It made no sense," Mr Allen said.
'Given up hope'
Police said they had found a vehicle hidden in the backyard of the Antioch property that matched the vehicle described at the time of the abduction.
Although Mr Garrido was previously visited by a parole officer, there was nothing odd noticed about the backyard.
The area occupied by Ms Dugard and her children was concealed by shrubs, rubbish bins and a tarpaulin.
Ms Dugard's stepfather, Carl Probyn, who witnessed the abduction on 10 June 1991, said he had "given up hope" she would be found alive.
"It broke my marriage up. I've gone through hell, I mean I'm a suspect up until yesterday," Mr Probyn, 60, told AP.
Mr Probyn saw the young girl being taken away by two people as she walked from her home to a school bus stop in South Lake Tahoe.
He said a stranger drove up and grabbed Ms Dugard, bundling her into a grey car even as she tried to resist by kicking and screaming.
Mr Probyn believed a man and woman were in the vehicle. Despite several false reports of sightings in the intervening years, Ms Dugard was never seen again.
"She sounds like she's okay," Mr Probyn said. "I hope she's been well-treated this entire 18 years.