Anon Nampa, a pro-democracy protest co-leader, has been detained in another case right after a court temporarily released him on bail in one.
The human rights lawyer was taken to Bangkok on Monday afternoon after the Chiang Mai Court approved a second round of his detention and released him on bail for a surety of 200,000 baht, according to Thai Lawyers for Human Rights.
The money reportedly came from the fund raised by a network of academics.
Mr Anon was detained after the release by Chana Songkhram police for his involvement in the Free Youth rally on Sept 19 at Thammasat University and Sanam Luang.
He was brought to the capital in a van, accompanied by a lawyer. It remained unclear whether he would be held at the Chana Songkhram police station or at the Border Patrol Police Region 1 headquarters in Pathum Thani province.
Mr Anon was arrested during the crackdown of a rally near Government House in Bangkok in the early hours of Oct 15, shortly after the serious state of emergency was declared in the capital.
Police acted on a warrant by Chiang Mai police for his role during a rally at Tha Pae in the northern province on Aug 9. He was charged with sedition under the Criminal Code, the penalty of which is up to seven years in jail.
Mr Anon was the first who publicly spoke about the need for the reform of the monarchy in decades. He advocated the changes in line with democracy with the King as head of state.