A search for a missing 11-year-old child, believed to be a boy, swept out to sea on the New South Wales Central Coast has been suspended on Sunday evening due to poor light.

Police and emergency services were called to The Entrance beach after 5pm (AEDT) on Sunday, following reports a swimmer had been spotted in trouble in rough conditions.

An extensive search was launched, with local police, Marine Area Command, Toll and Westpac rescue helicopters and local surf lifesavers searching for the child.

A source has told the ABC the child's family comes from a non-English-speaking background and are distraught.

NSW Police said the search for the child will resume at first light Monday morning.