The Dhaka Metropolitan Police arrested Workers Party President Rashed Khan Menon from Dhaka’s Gulshan area on Thursday.
DMP, however, did not disclose details regarding the arrest.
Earlier, a case was filed with a Dhaka court against Menon for making defamatory remarks about the Zia family.
Lawyer Ziaur Haque filed the case with Dhaka Metropolitan Magistrate Saiful Islam's court this morning.
The court directed the Police Bureau of Investigation (PBI) to investigate the case and submit a report.