The Criminal Court on Monday denied bail for Panusaya "Rung" Sithijirawattanakul on a lese majeste case involving her crop top outfit.
The court denied her bail after her lawyer Norasate Nanongtoom posted cash of 200,000 baht as a deposit.
The court said Ms Panusaya had repeatedly committed similar offences since she and four others were indicted by public prosecutors on June 29. She also violated the conditions set by the court in other cases, the court added.
The activist, clad in a crop top, walked at the Siam Paragon shopping centre on Dec 20 last year to protest the lese majeste law.
She was sent to the Central Women's Correctional Institution for detention.
She was at the court for a testimony appointment on Monday and the court set Jan 24 to examine the evidence.