Thaksin Shinawatra, who returned to Thailand from 15-years of self-exile, was shifted to a hospital early on Wednesday from a Bangkok prison to be treated for high blood pressure, local media reported, citing prison officials.

The former prime minister was admitted to the police hospital at 1 a.m., Thai-language newspaper Khaosod reported, citing Ayuth Sintoppant, director general of the Department of Corrections.

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Thaksin, 74, returned to Thailand on Tuesday and was ordered by the Supreme Court to serve an eight-year jail term for his role in various corruption cases. He was lodged in a private room in the medical ward of Bangkok remand prison.