Japanese coast guard authorities arrested the head of a tour boat operator on Wednesday over the high-profile sinking of a vessel off Hokkaido in 2022 that left 20 of the 26 people aboard dead and the six others missing.

The Abashiri coast guard station arrested Seiichi Katsurada, the 61-year-old president of Shiretoko Yuransen, based in the Shari, Hokkaido, over allegations including professional negligence resulting in death. The authorities did not disclose whether he has admitted the allegations.

Katsurada allegedly neglected his duty to ensure the safety of the passengers and crew of the Kazu I tour boat as the person in charge of the boat's operation during a tour around the Shiretoko Peninsula in eastern Hokkaido on April 23, 2022, causing the boat to sink and the 26 people aboard to die or disappear as a result.

As for the reason for the arrest, which came more than two years after the incident, the Japan Coast Guard's first regional headquarters in Otaru, Hokkaido, cited the possibility that the suspect could destroy evidence.

The authorities are also investigating the captain of the boat, who died in the incident at the age of 54.

The incident occurred off a waterfall area in the southwestern part of the peninsula. The Kazu I lost contact after one of the passengers spoke with a relative over the phone around 1:26 p.m. that day, during the tour. The boat is believed to have gone down a short time after that.

In its final investigation report on the incident, released in September 2023, the Japan Transport Safety Board said that a large amount of seawater gushed into the Kazu I through a hatch on its deck that opened due to the boat shaking, causing the boat to sink.