Seoul , South Korea ( CNN ) -- The head of the company that operated a passenger ferry that sank off South Korea last month killing more than 260 people was arrested Thursday , a senior prosecutor in the investigation told CNN . Kim Han-sik , chief executive officer of Cheonghaejin Marine Company , is being charged with `` causing death by negligence , as well as causing the capsizing of the ship in the line of duty , '' prosecutor Yang Joong-jin said . Kim also faces a charge of violating the ship safety act , Yang said , in connection with allegations that excessive cargo a played a role in the April 16 sinking . Investigators have said the cargo and the failure to tie it down properly was partially responsible for the sinking of the ferry Sewol , which was carrying 467 passengers and crew -- including more than 300 high school students on a field trip . Investigators said they 've indicted four employees of the ferry 's owner in the last two weeks , including a senior executive Tuesday . Details about the charges were n't immediately available . Authorities took aim at the cargo Tuesday , saying its weight was more than double the ship 's limit . The cargo was n't tied properly -- and the loosely tied goods helped cause the ship to capsize , Yang has said . Investigators had been probing the possibility the ship overturned because cargo shifted and forced the ship off balance . At least 269 people died in the disaster , which happened while the ferry was traveling from Incheon to the resort island of Jeju , off South Korea 's southwestern coast . Thirty-five people still are unaccounted for , according to the country 's coast guard . News of Kim 's arrest comes nearly a week after South Korean authorities searched Cheonghaejin Marine 's offices as part of a criminal investigation . This trip was n't the first time the ferry had excess cargo , a joint investigation team told reporters Tuesday . Since the Sewol began the Incheon-Jeju route in March 2013 , the ferry carried excess cargo 139 times , investigators said . Cheonghaejin Marine earned an extra 62 million South Korean won ( $ 62,000 ) for the excess cargo on the April 16 voyage , and nearly 3 billion South Korean won ( $ 2.9 million ) in extra profit for all of the excess cargo that the ferry carried since March 2013 , investigators said .
Kim Han-sik is chief executive officer of Cheonghaejin Marine Company . Among other allegations , he faces a count of violating the ship safety act . Charges against Kim are related to claims the ferry carried excessive cargo . Investigators say the cargo was partially responsible for the sinking .