Police searched the office of Prachatai, an online news outlet, on Tuesday after one of its reporters had been arrested and accused of breaching the referendum law.
Five policemen from the Suthisan station acted after the Criminal Court approved their request for a search warrant to look for evidence in connection with the detention of Taweesak Kerdpoka, a Prachathai reporter, and four students activists on Sunday.
A number of soldiers joined the operation but stayed outside the office in Huai Kwang district.
The search followed the arrest of its reporter and four other activists in Ban Pong district in Ratchaburi on Sunday, when they were there to show support for a group of people summoned to Ban Pong police for trying to set up a referendum fraud watch centre in one of their homes on June 16.
The five were accused of violating the referendum law and detained at the Ban Pong police station. All were released on bail by the provincial court on Monday.
Mr Taweesak travelled with the activists when he was apprehended.
"We came to check whether there were any documents in connection (with the incident in Bang Pong). We did not find anything linking with the case at the Ban Pong police station," Pol Lt Col Theerasak Sriprasert, the deputy superintendent of the police station, told Prachatai.
