The Supreme Prosecutors' Office on Monday attributed the cause of the April 16 ferry disaster to cargo overloading and the Sewol crew members' poor steering.
It added during a news briefing that the negligent rescue activities of the Korea Coast Guard contributed to the number of people who died in the sinking.
While the prosecution said it had verified that the deceased Sewol owner Yoo Byung-eun had glossed over the risks of extending the number of cabins in the vessel, the investigative agency dismissed the allegations that Yoo had conducted lobbying activities toward politicians or civil servants.
Yoo, who had led the Salvation Sect and Chonghaejin Marine Co., was found dead by a farmer on June 12, according to the prosecution and police.
Prosecutors concluded that Yoo "overlooked the risks of overloading the vessel with freight, pointing out the ferry's weakened ability to recover left-and-right balance when tilted due to an extension in the number of cabins."
Concerning the rescue activities, the prosecution said that the Mokpo District Coast Guard's patrol boat, dubbed the 123, failed to act swiftly to save lives even though it was the first ship to arrive at the scene after the Sewol ferry began to sink off Jindo Island, South Jeolla Province, on April 16.
The prosecution, however, sought relatively light punitive measures against senior officials at the Korea Coast Guard.
At the time of the incident, the ill-fated ferry was found to carry 3,606 tons of freight and cars, more than three times its recommended maximum capacity. The ship's operator, Chonghaejin Marine Co., reportedly depended on cargo delivery to compensate for declining passenger revenues.
Twelve Coast Guard officials at the vessel traffic service on Jindo Island were also found to have neglected their duty to properly monitor the ferry as it sailed nearby and failed to follow proper procedures in registering the Sewol's distress call.
Also, the captain of the Coast Guard, identified as a 53-year-old police lieutenant surnamed Kim, had removed some of the work records written on the day of the ferry sinking and filed new content, possibly from fear that his rescue team's poor initial response would be revealed.
The prosecution said that 88 people had been indicted for various shipping irregularities that have been cited as causes of the disaster.
Legal steps have been taken to confiscate a total of 122 billion won (S$134 million) in assets held by the owner family of the sunken ferry Sewol as part of the prosecution's efforts to hold the fugitive family liable for the deadly disaster, it added.
The prosecution has asked for the temporary seizure of assets both in Korea and overseas that are suspected to be proceeds of crimes by the late Yoo and his family.
The move is part of the prosecution's efforts to prevent the suspects from disposing of their assets before facing trial and to use the money to compensate the families of the victims, said a senior prosecutor.