The parents of missing Madeleine McCann said today that the reappearance of child kidnap victim Jaycee Lee Dugard 18 years after she disappeared "only makes us more determined" to find their daughter.
Jaycee was abducted at the age of 11 from her home in California in 1991 but has now been reunited with her mother after walking into a police station with her alleged captor and the two children he fathered by her.
Kate and Gerry McCann said today: "Once again this shows that children can sometimes disappear off the radar only to be found years later alive.
"It emphasises that we should never assume that someone is not alive without any evidence to support this. We should never give up
"This case only makes us more determined to find Madeleine. She is out there somewhere and somebody knows where."
The McCann's spokesman, Clarence Mitchell, said the couple, whose daughter disappeared in Portugal in 2007, sent their best wishes to Jaycee and her family "for a happier and peaceful future".
DNA tests are being carried out to confirm whether the woman who recently presented herself at Concord police station in California is Jaycee, who was snatched by two people in a car from a bus stop outside her home.
Convicted rapist Phillip Garrido, 58, and his wife Nancy, 54, have been arrested on suspicion of kidnapping the 11-year-old along with other offences, the El Dorado Sheriff's Department said.
Mr Garrido is also being held for investigation of rape by force, lewd and lascivious acts with a minor and sexual penetration, a spokesman for the Contra Costa Sheriff's Department said.
The kidnapped girl is believed to have borne two children, now aged 11 and 15, by her captor in a chilling echo of the case of Josef Fritzl, the Austrian man who fathered seven children with his daughter while she was imprisoned in his cellar.
A spokesman at the Sheriff's Department said Jaycee was apparently kept in a shed in the backyard of the Garridos' house where her children were born and brought up.
She has now been reunited with her mother, although officers admitted it "would be a long and ongoing process".
The Garridos were arrested on Wednesday after Mr Garrido - who was convicted of rape and kidnap in Nevada in 1971 - admitted the kidnapping under close questioning by a parole officer.
He had been called in after being seen with two children at the University of California, Berkeley.
It is understood Jaycee and the two children went to the meeting.
In a statement, the California Department of Corrections and Rehabilitation said: "The diligent questioning and follow-up by the parolee's agent of record led to Garrido revealing his kidnapping of the adult female.
"It was further revealed by Garrido that she was Jaycee Lee Dugard and that the children were his."
El Dorado County Undersheriff Fred Kollar said Jaycee and her two girls were kept in complete isolation in a compound at the rear of the house in Antioch, California, where Mr and Mrs Garrido lived.
They appeared to be in good health, but added that "living in a backyard for 18 years had taken its toll" on Jaycee.
The children have never been to school and never been to the doctor, he said.
He said: "The Garridos were taken into custody and an investigation led to their residence in Antioch. Two minors turned out to be children of Jaycee and the male suspect, Garrido. They, along with Nancy Garrido, were living together at the residence in Antioch since the original kidnapping."
The undersheriff described the compound where the family was imprisoned as a "series of sheds" with electricity and a "rudimentary shower".
He said: "A search of the residence revealed a hidden backyard with sheds, tents and outbuildings where Jaycee and the girls spent most of their lives.
"There was a vehicle hidden in the backyard that matched the vehicle originally described at the time of the abduction.
"The tents and outbuildings at the backyard were placed in a strategic arrangement to inhibit outside viewing and isolate the victims from outside contact."
He said one shed was soundproofed and could only be opened from the outside, while another had access to the backyard.
Jaycee's stepfather, the last person to see her in 1991 and a long-time suspect in the case, said he was overwhelmed to hear she had reappeared alive and well.
Carl Probyn, 60, said: "It broke my marriage up. I've gone through hell, I mean, I'm a suspect up until yesterday."
Describing the abduction on June 10, 1991, Mr Probyn said he saw someone reach out of a car and grab his stepdaughter before the vehicle sped away.
He said: "As soon as I saw the door fly open, the driver's door, I jumped on my mountain bike and I tried to get to the top of the hill but I had no energy. I rode back down and yelled at my neighbour, 911!"
The case attracted national attention and was featured on the television programme America's Most Wanted.
Mr Probyn said he eventually lost hope he would ever see his stepdaughter alive. He added that he was struggling to understand why Jaycee did not come forward earlier.
"I have a million questions, but I'm just delighted," he said.
The house in Antioch remained cordoned off with police tape as it was searched by FBI agents and the El Dorado County Sheriff's Department.
Neighbour Helen Boyer, 78, described the Garridos as nice and friendly and said they cared for Phillip Garrido's elderly mother.
"If I needed something, they would be the first I would call on," she said.