An American deported by Burma after swimming to the home of democracy icon Aung San Suu Kyi was undergoing medical tests in Thailand today amid growing concerns over his health, the US embassy said.

NONE John Yettaw flew out of military-ruled Burma on Sunday with Democrat US Senator Jim Webb, who secured his release by the junta from a sentence of seven years' hard labour.

Webb said that Yettaw, who is 54 and suffers from epilepsy and diabetes, was "not a well man" and had suffered what he called a medical episode even as he was being deported by Burmese authorities.

"Our primary concern is to ensure the health of Mr Yettaw," said Cynthia Brown, the spokeswoman for the US embassy in Bangkok, citing privacy reasons for not giving further details.

Diplomatic sources said Yettaw needed to be well enough to fly back home to Falcon, Missouri. He could fly back as early as late Monday on a commercial flight but there was no confirmation yet, the sources said.

Yettaw said he intruded on Suu Kyi's lakeside house in May on a "mission from God" to warn her about a vision that she would be assassinated, but his actions instead landed her with another 18 months' house arrest.

Suu Kyi, 64, and Yettaw were both convicted by a court in the junta-run nation on Tuesday.

Yettaw was hospitalised earlier this month after suffering a series of epileptic fits while being held in Rangoon's notorious Insein Prison, causing delays to the trial.

-AFP