The alleged leader of the anti-monarchy "Banpodj" network was arrested at a hotel room in Bangkok’s Makkasan area on Monday night, police said.
A combined team of police from the Technology Crime Suppression Division police (TCSD) and soldiers arrested Hasadin Uraipraiwan, alias Banpodj, at a room in the A-One Hotel on Soi Soonvijai about 8pm on Monday and he was later taken to the 11th Infantry Regiment for interrogation.
TCSD chief Siripong Timula said the arrest followed a police investigation that concluded Mr Hasadin, 64, had produced clips with the lese majeste content and distributed them among his network members. The suspect was reported to be hiding in the hotel room in Makkasan area, so authorities moved in to arrest him under martial law.
Mr Hasasin, who had a 200,000-baht bounty for his arrest, had no permanent job. He monitored online news and used the information to make up stories, mostly about the political situation, to provoke hatred towards the royal institution, Pol Maj Gen Siripong said.
Police spokesman Prawut Thawornsiri said earlier that a manhunt was under way for Mr Hasadin who was suspected of being involved in the production of hundreds of clips with lese majeste content.
He said a warrant was sought after police raided the suspect's house on Friday in Soi Sukhumvit 101 and seized equipment used in the production of lese majeste content.
During the raid, police found lese majeste content including fabricated audio clips uploaded to a server for members to download. Officers also seized financial documents and pirate CDs offered for sale to raise funds for the network's activities.
Pol Lt Gen Prawut said police were expanding the investigation to identify the network's financial supporters. Police set a reward of 200,000 baht for information leading to Mr Hasadin's arrest.
Two members of the Banpodj network were arrested last week. Saifon Inthasorn allegedly opened bank accounts to receive funds for the group's activities while Natee Pasomsap was allegedly hired to distribute the lese majeste content.
Police also were looking for those behind the recent distribution of a forged statement about the King's health. One man has been arrested for allegedly sharing it online.
Pol Lt Gen Prawut said warrants would be issued soon for others thought to be involved.