Protest leader Parit "Penguin" Chiwarak, being held in prison on charges relating to the lese majeste law, is suffering from minor ailments but is otherwise in fine condition, according to the Corrections Department.
Mr Parit was sent to Ramathibodi Hospital on Friday for a check-up after he began a hunger strike on March 16. He has since been referred back to the department's medical facility.
Thawatchai Chaiwat, the department deputy director-general and spokesman, said the medical facility has confirmed Mr Parit is experiencing gastritis and fatigue.
He is now able to sleep after being given medication and in fine spirits, said the spokesman, who added the 22-year-old is able to drink milk and take vitamins again which have been his main source of nutrition since he began his hunger strike.
Arnon Nampa, another Ratsadon protest leader, is in the middle of treatment for Covid-19 at Thammasat University Hospital and is being cared for by a team of specialists.
Mr Arnon contracted the coronavirus while in custody, according to the department.
Mr Arnon, who is also a lawyer, tested positive on May 5 and doctors believe he may have contracted it from Chukiat "Justin" Sangwong, a fellow protest leader who was found to be infected with Covid-19 on April 24.
Mr Chukiat, who was also indicted on lese majeste charges, spent time in the same cell as Mr Arnon.
Meanwhile, the Thai Lawyers for Human Rights said yesterday the Bangkok South Criminal Court has granted bail to Siripob Phumpuengput, co-leader of a student-led protest sub-group called Mor Sor Wor Khon Roon Plien.
Mr Siripob, who is another one facing indictment for lese majeste, was released on the condition he must not organise or join activities which tarnish the reputation of the monarchy and cannot leave the country.
