
Web director Jeeranuch Premchaiyaporn's computer was also confiscated during the raid.
Jeeranuch denied the allegation and that she would be interrogated only in front of her lawyer, the website said.
The web director has a duty to take care of all comments in the website and delete any improper ones. A Prachatai staff who did not want to be named said Prachatai consistency censors improper or rude comments in its website and web board.
Police accused the website of leaving lese majeste comments 20 days in the webboard.
Police and the Information and Communication Technology Ministry always issued their warning if such comments were founded in the website but there was no warning this time, the staff said.
There is no clear criterion to judge what kind of comments and contents in the web could be deemed as 'lese majeste', the official said. Police did not show the posted comments in question.
The computer law violators could be jailed for up to five years or fined not more than Bt100,000 or both.
The authorities have launched a campaign to crackdown websites accusing them of posting lese majeste contents. Many websites based inside and outside the country were blocked.
A dozen of individuals were arrested with the charge of lese majeste directly under the Penal Code such as former minister attach to Prime Minister Office Jakrabop Penkair, social critic Sulak Sivaraksa and Australian English teacher Harry Nicolaides while some of them were arrested under the computer law such Suwicha Thakhor and Jeeranuch.
A group of 50 international academics called the government on Wednesday to reform the lese majeste law and release all detainees under such charges.