Former prime minister Thaksin Shinawatra has undergone surgery and is in the process of recovery according to his daughter Paetongtarn, who said on Tuesday she does not know how long he must remain in hospital.
Ms Paetongtarn was speaking to reporters at Pheu Thai Party headquarters in Bangkok.
Thaksin had the operation last week and had yet to recover. His blood pressure was good some days, but not so good other days, she said.
Ms Paetongtarn did not give further details. She said reporters should ask Thaksin's doctors.
She said she really had no idea on how long her father would have to remain in hospital.
A chief physician at Police General Hospital on Tuesday confirmed Thaksin had undergone surgery.
Pol Lt Gen Dr Sophonrat Singhajaru said the former prime minister was operated on last week for several reasons. His condition was now safe and he was recovering.
On Monday, activists demanded an update on Thaksin's health, saying he had spent the last month in Police General Hospital, having been admitted almost immediatey after he was committed to prison, where he is serving a one-year sentence.
Ms Paetongtarn said that her family was considering applying for parole for Thaksin and they were aware of theregulations of the Department of Corrections.
Asked for a comment about a lese majeste case concerning Thaksin, Ms Paetongtarn said that resulted from a misunderstanding.
On Monday the Department of Corrections said that Thaksin would have to serve at least six months in prison before applying for a parole, or until late February.
The department will also decide if Thaksin needs continuous medical treatment outside prison.
Thaksin, 74, returned to Thailand on the morning of Aug 22 after 15 years in self-exile. He had been convicted and sentenced and charged with fresh offences during his absence.
The same day the Supreme Court ordered he be imprisoned for eight years for the three finalised cases. However, he was sent from Bangkok Remand Prison that same night to Police General Hospital for health reasons.
His jail term was reduced to one year by HM the King.