A girl who was kidnapped in the US as a toddler has been found seven years later, hundreds of kilometres away from her hometown in California.

Amber Nicklas disappeared in 2003, at just 13 months old, without a trace from a Los Angeles restaurant, authorities said.

The Associated Press reports the young girl was found in a court-ordered search of a property in Phoenix, Arizona, which is 597 kilometres from Los Angeles.

Police said a woman tried to hide Amber under a pile of towels in a bathroom shower as the property was inspected.

At first, she tried to claim she adopted the girl, but couldn't provide any paperwork to prove the story.

Amber's name and date of birth had been changed by her captors and they kept her out of school to avoid raising suspicion.

The girl appeared to be in good physical condition, authorities noted.

"The child seemed well cared for. She appeared well-nourished. The child was very happy," Captain Patrick Maxwell from the Los Angeles County Sheriff’s Department said.

Authorities were quick to shut down any parallels being drawn with the case of Jaycee Dugard, who was held captive for 18 years before being rescued a year ago.

"This wasn't like the Jaycee Dugard situation. Apart from being kept out of school she lived a semi-normal life.

"She wasn't locked in a bedroom or anything like that. She called these people mum and dad," he added.

Amber was snatched by her juvenile aunties during a court-arranged meeting between her foster parents and her biological mother seven years ago.

Two of the aunts were arrested at the time of the abduction, the third, aged just 13, took off with the baby and was never caught.

Captain Maxwell said police were still trying to determine exactly how the child came to be living in Arizona with the couple, who are not related to her.

He added that the parents who raised the girl would not be charged unless it was found that they had something to do with Amber's kidnapping.