SEOUL, May 8 -- Chief executive officer of the sunken South Korean ferry's operator, Chonghaejin Marine, was arrested Friday for overlooking the inveterate overloading, which led to the vessel's sinking.

Kim Han-shik, 72, has been detained by prosecutors for acquiescing the habitual overloading.

Kim was also charged with accidental homicide and violation of the ship safety law. Four other Chonghaejin Marine executives and staff were arrested earlier on the same charges.

Prosecutors sought an arrest warrant for Kim as they needed to detain him for questioning for up to 30 days.

The overloaded cargo has been seen as one of the main causes of the deadly sinking incident. The 6,825-ton ferry Sewol, which capsized off the country's southwestern coast on April 16 with 476 passengers and crew on board, has had no accidents in Japan for 18 years since it was built in 1994.

After acquiring the vessel, the Chonghaejin Marine had modified it to expand passenger cabins, raising the maximum capacity by 116 people to 956.

The vessel was loaded with 180 vehicles and 1,157 tons of freight, far exceeding the reported figure of 150 vehicles and 657 tons of cargo.

The ferry was known to have overloaded 139 times since its launch in March 2013, enabling the ship's operator to gain 2.96 billion won (2.9 million U.S. dollars) in illegal profit.

The ministry of ocean and fisheries launched administrative procedures to revoke a shipping license for the ferry's operator.

Meanwhile, prosecutors also sought an arrest warrant for the second son of Yoo Byung-eon, the ship's beneficial owner, on suspicion of masterminding all the illegalities linked to the sunken ship.

The second son, believed to be an heir apparent of Yoo, has disobeyed a summons from prosecutors for three times as he is staying in the United States.

As of Thursday, 269 people have been confirmed dead, with 35 still missing. The number of those rescued from the sunken ferry was 172.