Mike Arroyo, who remained in an Osaka hospital but has been declared stable, underwent heart surgery last year and was earlier said to have had a heart attack.

But doctors on board said he had stomach cramps and back pain and it was decided to make an emergency landing.

The president's husband plans to return to the Philippines once he is discharged from the hospital, Kyodo said.

Leaders from 21 Pacific Rim economies are gathering this week for the Asia Pacific Economic Cooperation (Apec) forum in the Peruvian capital.

There has not been any official confirmation from the Japanese government nor Philippines' local embassy on Mrs Arroyo's movements. -- REUTERS