The search is continuing for a 14-year-old boy missing off Christchurch's Sumner Beach.

Police say a helicopter is scanning the sea after the boy was reported missing at 3.20pm.

A spokesperson for the Sumner Surf Life Saving Club says their volunteers have now been stood down.

But he says they had five boats on the water at the peak of the search.

Police are still in attendance at the popular surf beach.