Health of Thailand's billionaire ex-PM Thaksin still a concern - doctor

FILE PHOTO: Exiled former PM Thaksin returns to Thailand

BANGKOK (Reuters) - Thailand's billionaire former premier Thaksin Shinawatra was still being treated in hospital on Friday and his condition remained a concern, a senior doctor said, three days after his historic return from self-exile.

Thaksin, 74, was hospitalised after suffering chest tightness and high blood pressure on the first night in prison, where he has been ordered to serve eight years for conflicts of interest and abuse of power.

"He is coughing ... and from the lung X-rays, heart and lung specialists are still worried," Soponrat Singhajaru, a senior doctor at Bangkok's police hospital, told reporters, declining to elaborate because of patient confidentiality.

Thailand's most famous politician arrived on a private jet to cheering crowds on Tuesday before being taken to a court, a prison and then hours later, a hospital, in dramatic events that overshadowed political ally Srettha Thavisin taking over as prime minister that same day.

The Pheu Thai Party that Thaksin founded will lead the next government. Rumours have swirled that his return could be part of a secret agreement with his rivals, which he denies.

His critics have complained he has been given special treatment, which the hospital has rejected.

Anti-Thaksin activist Tul Sittisomwong on Friday lodged a complaint with the hospital questioning whether the tycoon was really sick, or just dodging prison. Tul has asked for physicians from outside of the hospital to examine Thaksin also.

Photographs have been circulating widely on social media of the hospital's views of the Bangkok skyline and neighbouring golf course.

"All the rooms at the police hospital have this view," said Soponrat, the doctor at the hospital.

"Let's focus on giving treatment. That is our responsibility."

Despite living abroad for a total of 17 years, mostly in Dubai and Britain, since being ousted in a 2006 coup, Thaksin has remained a towering figure in Thai politics. Parties loyal to him had until this year won every election in the past two decades.

But his popularity and brash character clashed with Thailand's powerful network of old money elites and royalist generals, triggering a power struggle that is still being played out.

(Reporting by Chayut Setboonsarng and Panarat Thepgumpanat; Editing by Martin Petty)