Hundreds of Newcastle East Public School students have potentially been exposed to deadly asbestos after coming into contact with contaminated books.
Parents were advised on Wednesday morning that friable loose-fill asbestos had been found on rafters inside the school's heritage building as part of works to replace the building's asbestos roof during the school holidays.
It is not known how long the material had been exposed to the environment for.
Further testing revealed library books that had previously been housed in the building also tested positive for asbestos. The books have since been destroyed.
Department officials who spoke to parents did not rule out the possibility that children may have been exposed to asbestos contamination.
Education minister Sarah Mitchell has been contacted for comment.
