Kanoho previously said the passengers on board the helicopter had been in two groups - a party of two from one family and a party of four from another.
Kanoho declined to describe details of the wreckage out of respect for the victims' loved ones.
While the cause of the crash has yet to be determined, Kanoho said the area where the helicopter went down had experienced "some very bad weather" beforehand, adding that the chopper had crashed within its prescribed flight route.
The NTSB, which said it was sending a three-member team to investigate the crash, reported in May that there had been eight accidents involving Hawaii tour helicopters over the past five years, with four deaths and 18 injuries.
The agency made that report after a tour helicopter went down in a residential neighborhood on the island of Oahu in April, killing three people.
The latest crash was in Koke'e State Park in an area called Nu'alolo, a steep-sided valley north of Waimea Canyon State Park, according to a statement posted by the Kauai police department on Facebook.
Waimea Canyon is a tourist destination known as the "Grand Canyon of the Pacific," and police said the helicopter was last heard from at about 4:40 p.m. on Thursday, when the pilot radioed that the aircraft was just departing that area.
A search was launched a short time later, after Safari alerted authorities that the helicopter was 30 minutes overdue on its flight back to the airfield in Lihue on the island's southeast end, officials said.
A U.S. Coast Guard cutter vessel and helicopter search crew were immediately dispatched. The search was expanded at daybreak on Friday to include air, sea and ground teams from the Coast Guard, U.S. Navy, police, fire department and other agencies.
The missing aircraft was equipped with an electronic locator beacon, but no signals were received after it disappeared, the Coast Guard said.
According to its website, Safari offers aerial sightseeing excursions to Kauai's major attractions over the Na Pali Coast and Waimea Canyon. The Na Pali Coast, known for jagged green cliffs laced with towering waterfalls, is one of the most visited attractions on Kauai, the fourth-largest island in the Hawaiian chain.
