Port Chalmers School. File photo: Google Maps

A man has been arrested over a firearms incident that sent Port Chalmers School into lockdown last month, police say. 

Constable Liam Guthrie, of Port Chalmers, said police received a report of a man allegedly walking past the school with a firearm on May 18. 

"Police conducted a number of enquiries into this incident, resulting in the execution of a search warrant," Const Guthrie said. 

"During the search, a 36-year-old man was located and he was taken into custody without incident."

Police also said they located and seized an imitation firearm during the June 10 search and arrest.

The man is due to reappear in Dunedin District Court at a later date, charged with carrying an imitation firearm without reasonable excuse.

Constable Guthrie said police understand the concern the public may have had following this incident and hope this arrest provides reassurance to the community.

"We would also like to thank the members of the community who have assisted us in our enquiries."

Anyone with further information regarding this matter can contact police online at 105.police.govt.nz or call 105, quoting file number: 260518/4942

Alternatively, you can provide information anonymously through Crime Stoppers on 0800 555 111 quoting the same file number.