The return of an American girl kidnapped 18 years ago has been described by her stepfather as a “miracle”.

Police say 29 year old Jaycee Lee Dugard spent the majority of her life hidden in a secret backyard and has had two offspring with her kidnapper.

Carl Probyn saw his stepdaughter for the first time since 1991, when he witnessed two individuals force the then 11-year-old girl into a vehicle as she was simply walking to a school bus stop.

“After 18 years you do give up hope. I mean, this is a miracle – 18 years. When was the last time you heard of somebody recovering somebody after 18 years?” he said.

Authorities have said that there was no indication that the kidnappers knew Miss Dugard while no traces was left from girl or the car.

Tuesday police got a break in the case when a man tried to enter the grounds of the University of California in Berkeley, accompanied by two girls to pass out religious leaflets.

A campus police officer discovered that Philip Garrido, had been previously convicted of rape and kidnapping.

Since Garrido is a registered sex offender, it is prohibited for him to be near children. His parole agent was immediately contacted.

Undersheriff Fred Kollar says Garrido showed up with wife Nancy, the two girls and a woman named “Alissa”.

“The parole agent had never seen these individuals, Alissa and the two young children, during his visits at the house,” Kollar said.

“He thought that the females in Garrido’s company were suspicious and contacted the Concord Police Department.”

Alissa was later identified as Jaycee Lee Dugard.

“Subsequent interviews with Jaycee and the Garridos provided information that only the victim and the kidnappers could know. DNA confirmation is being sought to confirm Jaycee’s identity,” he said.

The two girls – aged 11 and 15 – are Garrido and Miss Dugard’s children.

We would like to thank www.abc.net.au for quotes used in this article.