Prime accused Badal has been arrested for stripping and molesting a woman in Noakhali after the incident went viral on the social media.
The media wing of Rapid Action Battalion (RAB) confirmed this on Monday morning.
Besides, Delwar-group chief Delwar was arrested from Narayanganj in possession of arms in connection with the incident.
Earlier, Begumganj police station officer-in-charge Harun-or-Rashid Chowdhury confirmed to Prothom Alo the arrest of two more people on Monday morning.
A suspect, Rahmat Ullah, 41, was arrested on Sunday night and another suspect, Abdur Rahim, 20, was arrested on Sunday afternoon.
Police sources said the victim, 37, filed two cases with the Begumganj police station on Sunday. Nine people were made accused in the cases.
The incident took place at Eklashpur union of Begumganj upazila in the beginning of September.
OC Harun-or-Rashid Chowdhury said the victim filed two separate cases with the Begumganj police station at around 11:45pm. One case was filed under the Woman and Child Repression Prevention Act and another under the Pornography Control Act.
Speaking to Prothom Alo on Sunday, Noakhali district superintendent of police Alamgir Hossain said they came to know the matter after the video of the incident went viral on the social media.
The district police boss said they took instant measures and rescued the victim.