The Jakarta police arrested Hatta Taliwang, an activist and director of the Soekarno-Hatta Institute, at his apartment in Bendungan Hilir, Central Jakarta, at 1 a.m.
"At 2 a.m., he was declared a suspect and detained," Head of Public Information of the National Police Headquarters Senior Commissioner Martinus Sitompul said at a press conference.
He explained the suspects detention was necessary as police considered him a flight risk or potential repeat offender and feared he may eradicate evidence.
"Of course the decision is very subjective, based upon the investigators view. The investigators considered the detention necessary," he remarked.
He noted the suspect would continue to be subject to further questioning while he was in custody.
Hatta, who is also a former member of parliament, has been charged with allegedly violating Article 28 (2) in conjunction with Article 454 (2) of the law on information and electronic transactions.
Martinus linked Hattas arrest with the arrest of 11 others last Friday for allegedly committing treason.
"The person concerned has posted statements on social media that express hatred on sensitive issues related to SARA (religious, ethnic, tribal and inter-group)," he remarked.
He said the police had confiscated a cell phone, a book, and some documents from him.
Last Friday (Dec 2), police arrested singer Ahmad Dhani; former army general Kivlan Zein; former army general Adityawarman; and activists Ratna Sarumpaet, Firza Husein, Eko, Alvian, and Rachmawati for allegedly being involved in a treason plot.
Although they were named suspects, they had not been detained, but three of them - Sri Bintan Pamungkas, Jamran, and Rizal - had been detained for allegedly violating the information and electronic transactions law and Article 107 of the Criminal Code in connection with calls they made on social media to instigate the public.
(Reported by Benardy Ferdiansyah/Uu.H-YH/INE/R-BSR/F001)