By Agence France Presse
The timing of his terrified message -- "Save us. The ship is sinking" -- has fuelled anger over the slow response of the Sewol's captain and crew as the disaster unfolded.
The confirmed death toll stood at 162 on Thursday, with 140 still unaccounted for -- their bodies believed trapped in the ship that capsized in circumstances that have yet to be fully explained.
Yonhap news agency said divers had retrieved the boy's body from inside the ferry on Thursday morning and it had been identified by his parents.
A DNA test was being carried out to formally confirm his identity, Yonhap said. The boy was one of 325 students from the same high school who were on the ferry, bound for the southern resort island of Jeju, when it capsized.
During his 119 call, Choi was bombarded with questions about the ferry's coordinates and the number of people on board.
A coastguard official later told reporters that emergency services had mistaken him for a crew member.
The captain and 11 crew members have either been arrested or taken into police custody awaiting charges.