Protest leader Parit "Penguin" Chiwarak has begun a partial hunger strike in prison, consuming only milk, sweet drinks and mineral water, Thanakrit Jit-areerak, secretary to Justice Minister Somsak Thepsutin, said on Wednesday.
Mr Thanakrit said he went to the Bangkok Remand Prison to visit political activists being detained there to see their living conditions.
He spoke with Mr Parit, a co-leader of the Ratsadon group, who told him that he was taking only milk, sweet drinks and mineral water, he said.
Mr Parit announced he was going on a hunger strike on Monday, when he and other Ratsadon leaders appeared before the Criminal Court for hearings related to charges involving the Sept 19-20 protests at Thammasat University and Sanam Luang.
He said he would go on a hunger strike until all people accused of lese majeste and other political charges were allowed bail.
Mr Thanakrit said he asked prison officials to take a good care of Mr Parit. If he was found to develop health problems he could be transferred to the Corrections Department's hospital, which is next door to Bangkok Remand Prison.
He had also told the officials to make sure that all surveillance cameras in all detention zones were functioning properly - to build confidence regarding the treatment of detainees.
Justice Minister Somsak Thepsutin had ordered that a working committee chaired by Wallop Nakbua, deputy permanent secretary for justice, gather facts about the care given to leaders of the Ratsadon group being held on political charges at the prison, to provide clear information to the public, beyond doubt, he said.
It would report on Wednesday afternooon, he said.