On Wednesday, prosecutors have decided to expand its investigation on the doomed Sewol ferry as investigators have confirmed that the ship's cargo was three times more than the recommended maximum weight. The Wall Street Journal said prosecutors has already started their investigation on the owner of the sunken ferry, which began with a broad ban for Chonghaejin Marine Co officials to leaving the country. The company's headquarters, its affiliates, the home of the firm's owner and the offices of his other companies were also raided as well.

The aggressiveness of the investigation also led prosecutors to collect documents from the Korean Register of Shipping. The government-commissioned inspector is assigned to conduct safety checks on the ship earlier this year. Aside from looking into the negligence and the other potential violations of the ferry's owner, the expanded investigation has also delved into the possibility of the inspector failing to enforce regulations and conduct proper safety checks on the ship, WSJ reported.

According to radio communication with the Korean Shipping Association, Sewol left the Incheon port on Tuesday last week with 3,608 tons of cargo. A Korean Register official said on Wednesday that the maximum recommended weight for the doomed vessel was only 987 tons.

WSJ said that although the prosecutors are still looking for answers as to why the vessel had sunk and endangered the lives of over 300 people, the investigation had been focused mainly on Chonghaejin Marine in the past few days since the tragedy.

The official death toll from the maritime incident has already risen to 150, and that 152 are still unaccounted for. According to a spokesman for the country's coast guard, divers have recovered more bodies from the upper decks of the doomed ship, majority from a multibed economy cabin on the fourth deck.

Citing a Korean register report, WSJ said the investigation is also looking into the possibility that the ship was not safe for operation following its redesign last year. Sewol reportedly underwent modifications like extra passenger cabins and others which increased the passenger capacity and weight of the ship by over 150 people and 240 tons respectively.