Newborn baby snatched from hospital cot found living with kidnapper 18 years later.

A newborn abducted from a hospital 18 years ago has been found ‘alive and well’, living with her kidnapper.

Just eight hours after she was born on July 10, 1998, Kamiyah Mobley was taken from University Medical Center in Jacksonville, Florida, by a woman posing as a nurse.

Her disappearance sparked an intensive investigation that saw authorities follow up on more than 2500 leads. But it was a single tip received last year that lead the Jacksonville Sheriff’s Department 300km north to South Carolina.

There, almost three hours away in the town of Walterboro, they found Mobley living under a different name with a 51-year-old Gloria Williams, the woman she had been raised to believe was her biological mother, reports First Coast News.

In Friday's press conference Jacksonville Sheriff Mike Williams said the missing woman's identity was confirmed by a DNA test.

Williams said she was overwhelmed to learn what had occurred, but is otherwise in good health.

“She’s taking it as well as you can imagine," he said. "She has a lot to process.”

Mobley's biological family was reportedly "elated" when they learned of her discovery and have since spoken to her via video chat.

“She looks just like her daddy,” her paternal grandmother, Velma Aiken told The Associated Press. “She act like she been talking to us all the time. She told us she’d be here soon to see us.

“I always prayed, ‘Don’t let me die before I see my grand baby’,” added Aiken. “My prayer was answered.”

On the tenth anniversary of her kidnapping, Mobley's mother, Shanara Mobley, told the Florida Times-Union that on each of her daughter's birthdays, she set aside a piece of cake, wrapped it in tinfoil and placed it in the freezer, just in case.

"It's stressful to wake up every day, knowing that your child is out there and you have no way to reach her or talk to her," she said.

Williams has been charged with kidnapping and interference with custody.