Mr Jose Miguel Arroyo, 62, was accompanying the president on a flight to Peru for the Apec summit when he fell ill, forcing an emergency landing in Japan on Friday night.

His doctor Juliet Cervantes said Mr Arroyo had suffered a severe abdominal pain accompanied by vomiting due to 'acute infectious diarrhoea', and that the incident was not related to the heart surgery he underwent last year.

'I'm okay. Doctors have cleared me and I can go home already,' a weak Mr Arroyo told a crush of reporters outside the hospital as he was picked up by his sons.

'What I suffered in the plane was excrutiating abdominal pain and so the doctors decided to land the plane somewhere near, in Japan at that time. And I'm glad that it's over,' he said. 'I did not have a heart attack, thank God.'

Vice-President Noli de Castro had told Philippine television on Saturday that Mr Arroyo had suffered a heart attack on the flight.

The president went on to Peru for the summit 'because there was nothing to worry about', Mr Cervantes told reporters.

Mr Arroyo said he was under strict instructions to return for medical evaluation later in the week. -- AFP