South Korean boxer Choi Yo-sam, who lapsed into a coma last week defending his World Boxing Organisation intercontinental flyweight title, has been declared brain dead, a hospital official said on Wednesday.

Choi, who won the December 25 fight on points, was sent to the canvas just seconds before the end of the 12th and final round by a hard right to the jaw from Indonesian challenger Heri Amol, who landed a flurry of punches before the bell.

Choi, 33, staggered to his feet but collapsed shortly after the bout. He left the gymnasium on a stretcher and never regained consciousness. Doctors said he suffered cerebral haemorrhage.

"Doctors have pronounced him brain dead," said a spokesman for the Asan Medical Centre, the Seoul hospital that has been treating Choi.

Choi's family is considering donating his organs, said Han Bo-young, vice-president and secretary general of Korea Boxing Commission.

The fight brought back memories of a 1982 title bout in Las Vegas [Images] between lightweight champion Ray "Boom Boom" Mancini of the United States and Kim Duk-koo, where the South Korean challenger died from injuries sustained in the fight.