Photo/Illutration The curtains are drawn inside the office of Shiretoko Pleasure Boat in Shari, Hokkaido, on May 2. (Toshinari Takahashi)

SHARI, Hokkaido--The Japan Coast Guard searched the office of a sightseeing boat operator here on May 2 for evidence of professional negligence involving the deadly sinking of a tour vessel in rough and stormy seas.

The Coast Guard's Abashiri Maritime Security Office conducted the search of the office of Shiretoko Pleasure Boat. The company operated the Kazu I, the tour boat that sank off Shiretoko Peninsula on April 23.

Noriyuki Toyoda, the captain of the boat who remains missing, and Seiichi Katsurada, the president of the company, are under suspicion of professional negligence resulting in deaths.

The Coast Guard will investigate the company’s decision to allow the Kazu I to leave Utoro Port while gale and high surf warnings were in effect.

It will also look into the broken antenna at the company's office that prevented it from receiving a signal from the boat's ham radio.

The Kazu I left the port at 10 a.m. on April 23. It was scheduled to return to port after finishing the three-hour tour, which was to visit Kashuni Falls on the Shiretoko Peninsula, a World Natural Heritage site. 

Also on the tour's itinerary were locations for passengers to observe brown bears and white-tailed eagles, before turning at Cape Shiretoko.

However, after 1:13 p.m. that day, the Kazu I reported that the boat was taking on water near the falls and that its engine had stopped operating.

Contact was lost with the vessel after 2 p.m. when the Kazu I reported that it was listing at 30 degrees in its final transmission. 

According to the First Regional Coast Guard Headquarters in Otaru, Hokkaido, and other sources, 26 people were aboard the boat. They were 24 passengers including two children, the captain and another crew member.

So far, 14 bodies have been found over large areas of the sea including near Cape Shiretoko. All were confirmed to have drowned. 

The Kazu I was located on the bottom of the seabed on April 29, 120 meters below the surface.