Thailand news website Khaosod reported protest leader Sombat Boonngam-anong had been arrested by police officers of the Technology Crime Suppression Division who are working with the army, according to The Associated Press.
Sombat had been traced on the internet by the National Intelligence Agency and was hunted after defying an order from the new military government to report to the authorities, and went into hiding, going online to organize anti-coup protests in Bangkok, the AP reported.
The military coup captured top organizer of protests during its recent takeover and launched a probe into the finances of the former elected prime minister, according to the AP.
Sombat was the first to announce his own arrest, posting a message Thursday night on his Facebook account saying simply, "I've been arrested," the AP reported.
Thai media later reported that Sombat, also known as Nuling, was captured in a house in Cholburi province, about two hours east of Bangkok, according to the AP.
Sombat was one of the first people to organize protests against Thailand's previous coup in 2006 and became known for imaginative and non-violent tactics, the AP reported.
The new government has warned that it is closely monitoring online activities, and plans to expand its surveillance capabilities, according to the AP.
Several dozen people have defied the order to turn themselves in, and some are known to have fled to neighboring countries, the AP reported. The junta has declared that those who don't surrender themselves may be subject to a two-year jail term.
The military has detained people from both sides of the political divide, but a disproportionate number are Thaksin's red-shirt supporters, according to the AP. It has closed down radio stations of his supporters and frozen the bank accounts of some.