Police inquiries into the origin of the phone call were continuing, he said. It was too early to say whether the call originated within New Zealand or overseas.
Police were grateful for the patience of and assistance from locals, tourists and other emergency services, he added. Eight officers were involved, along with firefighters from the Russell and Paihia brigades. St John Ambulance medics were on standby.
Duke co-owner Riki Kinnaird said it was the first time such an incident had occurred at the hotel.
"This kind of thing may have been common in the 1800s, but not now," he said, but the hotel's procedures for such an event had worked well, and the police and fire crews had been "awesome".
He singled out local Constable Mike Gorrie for special mention. He had arrived on the scene quickly, and his guidance and presence had been very reassuring.
"It's just really disappointing we've been the target of something like this. It's affected more than just our business; half of Russell was cordoned off," Mr Kinnaird said however.
Meanwhile, the conference delegates were taken by ferry and a local tour bus to Charlotte's Kitchen, a Paihia restaurant. Passenger ferries were suspended during the scare but the car ferry continued operating.
At Russell School, a few blocks from the Duke, principal Melissa Jackson took advice from police before letting the children out of their classrooms for lunch. Extra teachers and parents were placed around the school grounds as a precaution, and the lunch break was cut short.
Many Cass St businesses remained closed even after the cordon was lifted. One that did reopen was Bay of Islands Ink, where tattooist Dante Regeling was surprised to see at least six police cars and three fire engines turn up. His business was not greatly affected, but the food outlets across the road had been packed when the order to evacuate came.
"It was probably the biggest thing that's happened here since Hōne Heke cut down the flagpole," he said.