Cape Town: A baby stolen from her sleeping mother's arms shortly after birth has been found by the family through an astonishing coincidence 17 years later, South African police say.

A 50-year-old woman has been arrested and charged with kidnapping after pupils noticed a remarkable likeness between the 17-year-old and her younger biological sister, who started attending the same school this year.

Celeste Nurse, right, the mother of a girl that was kidnapped as a baby 17 years ago, leaves the court after attending the appearance of a woman suspected of the kidnapping in Cape Town, South Africa. Credit:AP

DNA tests have confirmed that the older girl is the daughter of Celeste and Morne Nurse, who was snatched from Groote Schuur hospital as a three-day-old baby named Zephany in April 1997, local media reported.

The parents, who later had three more children, have celebrated Zephany's birthday every year since she was kidnapped, never giving up hope that their first-born child would come back to them some day, the Cape Argus said.