Lin Sung-huan, head of the East Asian and Pacific Affairs Department of Taiwan's foreign ministry, said Ople died after he was taken to a hospital in northern Taiwan's Taoyuan county for emergency treatment.
Taiwan's foreign ministry said earlier that Ople was taken ill late on Saturday while on a Japan Asia Airways flight to Bangkok.
"The plane was forced to make an emergency landing at Chiang Kai-shek airport at around 14:30 GMT on Saturday," foreign ministry spokesman Richard Shih said.
He said Ople was taken to hospital, but declined to give details of Ople's illness.
"The (details of the) illness should be given by Ople's family... We respect their desires," Shih said.
Taiwan's state-run Central News Agency said Ople did not show any sign of life when a doctor at the airport was called to the aircraft.
"The plane was forced to make an emergency landing at Chiang Kai-shek airport at around 14:30 GMT on Saturday"
Taiwan's foreign ministry spokesman
In Manila, a Filipino official said Ople had suffered a heart attack, although this could not be independently confirmed.
The Philippines foreign office said in a statement that Ople planned to go to Manama, Bahrain, from Bangkok before President Gloria Arroyo's visit there "when his flight from Tokyo had to be diverted to Taipei after complaining of breathing difficulties".
Manila does not recognise Taiwan which China regards as part of its territory waiting to be reunified by force if necessary, but the Philippines maintains close economic ties with the island.