Police have arrested Gazi Salauddin Tanvir, a former joint member secretary of the National Citizen Party (NCP), in a Cyber Security Act case registered at Bogura Sadar police station.
Bogura Sadar police station officer-in-charge Ibrahim Ali confirmed the arrest and said Tanvir was being taken to Bogura following legal procedures.
The case concerns allegations over a social-media post about Prime Minister Tarique Rahman.
Mafthun Ahmed Khan Rubel, president of Bogura Sadar Upazila BNP, filed the complaint.
The stated filing date is inconsistent, with 2 August and 3 August both given.
The complaint alleges that a post published from Tanvir's Facebook account on 29 July was defamatory and provocative.
It further alleges that the post sought to damage the prime minister's reputation and create public confusion and tension.
Both accounts state that Tanvir later removed the post and publicly apologised after criticism.
The accounts also differ on the timing of the arrest, placing it either at about 4am on 4 August or during a Tuesday-night operation in Dhaka.
NCP disciplinary action against Tanvir is described as either removal from the party or removal from his joint member secretary post.