"Cordons will be in place in the Aotea Quay area around the ferry terminal and people are advised to avoid the area while the incident is dealt with," police initially said in a statement.
But those cordons were stood down shortly before 11.30am after police were able to confirm ther was "no suspicious item onboard and no cause for concern".
"Interislander are working to move passengers to their destinations," police said.
"Enquiries are continuing as to the identity of the person who made the threat."
