Oscar-nominated child star Keisha Castle-Hughes has announced she is pregnant to her teenage boyfriend and is to give birth next year.

The 16-year-old New Zealand actress is "extremely happy about it", her agent Gail Cowan told the Herald on Sunday newspaper.

Neither Castle-Hughes or her mother could be contacted, nor could the baby's 19-year-old father.

Castle-Hughes became the youngest actress nominated for a best actress Oscar when she was short-listed for the 2003 Academy Awards for her breakthrough role in the New Zealand film "Whale Rider".

She had a brief role in "Star Wars: Episode III - Revenge of the Sith" and will next be seen as Mary in "The Nativity Story", about the life of the Virgin Mary before the birth of Christ, set for release on December 1.

The story, to be told with a strong female perspective, will follow Mary and Joseph's life before the birth of Christ as their love, faith and beliefs are tested.

Castle-Hughes and Bradley Hull, the father of her baby, have been dating for three years, but he was not allowed to accompany her to the Oscars because her representatives reportedly had concerns about the age difference.