Russia's Investigative Committee has detained the deputy director of a company that owned the trawler that sank in the Sea of Okhotsk on Thursday, claiming 56 lives, the law enforcement agency said on its website Monday.
Thirteen people remain missing in the aftermath of the incident.
A search warrant was also issued in relation to the owner company's director, who is currently in South Korea, the statement said.
"The investigators believe these will not be the only people who will be criminally charged over this shipwreck and deaths. The investigators will check everybody, including the government officials who were responsible for ensuring the safety of the fishing vessel," according to the statement.
Earlier on Sunday, Oleg Kozhemyako, acting governor of the Sakhalin region, where the trawler was based, said that the vessel was carrying only about a fifth of the ballast it should have been, making it severely unstable, The Associated Press reported.