Thaksin Shinawatra was transferred from Bangkok Remand Prison to the Police General Hospital at 12.20am Wednesday, suffering from chest pain, hypertension and low blood oxygen, the Department of Corrections said.
A source said the 74-year-old former prime minister arrived at the Police Hospital at about 12.30am.
He was installed in a private room, Royal Suite 1401, on the 14th floor of the Maha Bhumibol Rachanusorn 88 Phansa Building, the source said. There are two rooms on the floor, which is reserved for special patients.
Deputy director-general Sitthi Sutivong said on Wednesday morning that a warder at the prison had reported that Thaksin could not sleep, had chest pain, hypertension and low blood oxygen, while in quarantine in zone 7 of the prison.
Thaksin was admitted to the prison on Tuesday afternoon after his return to Thailand on Tuesday morning, following a court appearance.
A doctor at the Corrections Hospital reviewed Thaksin's symptoms and considered his medical treatment records from overseas hospitals, which diagnosed him with underlying illnesses including ischemic cardiomyopathy, hypertension, pulmonary fibrosis and spondylosis. Ischemic cardiomyopathy required special observation.
As the Corrections Hospital lacked some medical equipment, the doctor decided to transfer Thaksin to Police General Hospital, which was better equipped, for his safety.
Thaksin was admitted to Police General Hospital for treatment and prison staff were deployed there in line with the regulations of the Department of Corrections, Mr Sitthi said.
The Police General Hospital said in a statement on Wednesday that a Corrections doctor checked Thaksin's symptoms and found his illnesses required urgent treatment. As the Department of Corrections lacked specialised doctors and equipment, Thaksin was referred to Police General Hospital.
Referrals of prisoners to Police General Hospital were normal in accordance with a memorandum of understanding the Department of Corrections signed with the police on May 1, 2020.
The Police General Hospital had the proper medical equipment and enough staff to assist with security measures for prisoners, Police General Hospital said.
On Tuesday Thaksin was admitted to Bangkok Remand Prison to begin serving his eight-year jail term after returning to the country in the morning. The Supreme Court ordered his eight-year imprisonment based on his finalised cases. The Department of Corrections earlier said Thaksin, who returned from 15 years in exile, was eligible to apply for a royal pardon from his first day in jail.