The military on Saturday rearrested Thanapol Eawsakul, editor and publisher of 'Fa Diew Kan' (Same Sky) magazine, for allegedly breaching the conditions of his release.
Thanapol had been detained by Crime Suppression police for seven days under martial law.
Police Lt-General Notheerit Harnsanaerak, an investigator, said the military could hold Thanapol in custody up to seven days – but they may release him tomorrow.
He may be sent to another remand centre, depending on the charges he will face, but he can still be visited by relatives and his lawyer at present.
A source said the military called Thanapol on Saturday and asked him to meet at a coffee shop on Phahon Yothin Soi 7.
After, Thanapol was arrested and taken to the Second Cavalry Division headquarters at Sanam Pao for questioning before being handed over to Crime Suppression police.
Thanapol was rearrested because he posted a message on his Facebook page. The military has not yet pressed any charges against him.
He was one of several journalists summoned by the National Council for Peace and Order. He was wanted in connection with an anti-coup protest in front of the Bangkok Arts and Culture Centre on May 23.
After reporting to the NCPO, he was detained for seven days under martial law and freed on the condition that he does not travel abroad or conduct political activities in a way that could sow strife in society.
Separately, nationalist Veera Somkwamkid and General Boonlert Kaewprasit were also released at 3pm yesterday after they reported to the NCPO in the morning at the Army Auditorium.
Boonlert later told reporters that he had promised to the NCPO to seek approval from the junta before organising any political activity.
On Sunday he had hosted a reception at the Royal Turf Club for Veera, who was pardoned last week after spending over three years in a Cambodian prison.