An investigation's underway at a Canterbury school after a student was allegedly beaten unconscious by a classmate

The 14-year-old boy's family claims he was punched and kicked until he blacked out at Ashburton College on Friday.

The assault reportedly occurred after a classmate began saying slurs at the victim.

The boy's mother says she was disheartened by the school's initial response.

Principal Simon Coleman says the behaviour's unacceptable - and it took time for a teacher to intervene, because the incident happened in a space outside the classroom.

Police are making enquiries.