Billionaire Thaksin, 74, was hospitalised with high blood pressure and chest tightness within hours of his dramatic return to Thailand in August from 15 years of self-imposed exile to serve an eight-year sentence for abuse of power.
His sentence was commuted to a year following a royal pardon.
The corrections department last week extended his stay in a police hospital, citing the need to monitor his health.
"Based on the criteria, Thaksin qualifies for a special parole," Corrections Department Deputy Director General Sitthi Sutivong told reporters in answer to a question on whether Thaksin could be released in February.
Sitthi said his department had yet to receive an official request from the Bangkok Remand Prison for his parole.
Thaksin was ousted from power in a 2006 military coup and has been at the heart of 17 years of on-off turmoil in Thailand, influencing politics from exile.
Thaksin, a former telecoms tycoon and owner of Premier League football club Manchester City, was accused by the military of corruption, cronyism and abuse of power.
He was sentenced to jail in absentia in 2008. His sister, Yingluck Shinawatra, was ousted as prime minister in another military coup in 2014.
Thaksin received a rock star reception as a fugitive on his return to Thailand in August, with crowds cheering his arrival by private jet and policemen saluting him before escorting him to court and then jail.
The same day, his ally and real estate mogul Srettha Thavisin was elected prime minister by parliament.
Thaksin has repeatedly denied still being in politics and says he is retired.
