Jaycee Dugard as she looked in 1991. (AFP)

San Francisco, Aug. 28 (Reuters): A California girl abducted at age 11 in 1991 has been found alive, police said yesterday.

They added that her kidnapper apparently fathered two children with her and kept all three living in tents and sheds behind his house.

Jaycee Dugard had been missing since she was abducted near her home in South Lake Tahoe, east of San Francisco, on June 10, 1991, by two people in a grey sedan.

“It’s a pretty spectacular story just to find someone like that. Someone we assumed was dead,” said Bill Clark, the chief assistant district attorney for El Dorado county, an area east of Sacramento that stretches into the Sierra Nevada.

Dugard’s alleged kidnapper, Phillip Craig Garrido, 58, a registered sex offender in California who served time in prison for rape and kidnapping, and Nancy Garrido, 54, were in custody after being arrested on Wednesday, police said.

Dugard was healthy, El Dorado policeman Fred Kollar said, but “living in a backyard the last 18 years must take its toll”, he added.

“None of the children had ever been to school, none had been to a doctor, they were kept in complete isolation in this compound, if you will, at the house,” Kollar said. Suspicions were first raised after Garrido tried to enter the University of California at Berkeley campus to pass out leaflets with his two daughters. His interaction with the two female minors, aged 11 and 15, raised suspicion.