The body of a South Korean boy whose shaking voice first raised the alarm that a passenger ferry with hundreds on board was in trouble has been found, his parents believe, but a DNA test has yet to confirm the find, media said on Thursday.

His parents had checked his body and clothes and concluded he was their son, the Yonhap news agency said. The crew had told the children to stay put as the ferry sank.

The Sewol sank on March 16 on a routine trip from the port of Incheon, near Seoul, to the southern holiday island of Jeju. Investigations are focused on human error or a mechanical fault, with media saying the ship was three times overloaded, with cargo poorly stowed and inadequate ballast water.