National Citizens Party (NCP) Central Joint Secretary Tarek Reza was released on bail from jail in Jhenaidah on Monday morning.
A team from Jhenaidah Sadar Police Station arrested him around 6:30pm on Sunday from in front of the Family Zone auditorium near Jhenaidah Stadium.
Tarek Reza had called an emergency press conference at the auditorium in Jhenaidah town that evening, and officers took him into custody soon after he arrived.
At the time of the arrest, Jhenaidah Sadar Police Station Officer-in-Charge Asadujjaman was present with police, a plainclothes special team and members of intelligence agencies.
Later that night, he was sent to jail under a court order.
Jhenaidah Sadar Police Station Officer-in-Charge Asadujjaman said a case was filed at the station on Saturday against Tarek Reza and several others over allegations of assault, vandalism and threats to kill.
He added that police operations were continuing to arrest the remaining accused.