Canterbury police are investigating the source of the initial report which sparked last night’s widespread search off Sumner beach.

Police were called about 9pm after receiving a report that three people were swept out into the water near Shag Rock in Sumner.

Extensive emergency resources were called in to help search the beach waters including a rescue helicopter, rescue boats, firefighters, police units and St John ambulance.

However, a police spokeswoman says the report was third-hand information and an extensive search failed to locate anything to suggest people were in trouble in the area.

She says inquiries into the incident are ongoing.

Chris Lynch Media has contacted the man believed to have made the initial report.

The man maintains he did the right thing despite leaving the scene before emergency services arrived, claiming he had to catch the last bus home.

The man’s Facebook posts, reporting the incident, were widely shared on community Facebook pages – with no credible attribution or confirmation from emergency services.