Md Shah Poran, 28, was picked up from the Kabila Bazar area of Burichang upazila around noon on Thursday, RAB-11 Commanding Officer Lt Col HM Shazzad Hossain said during a briefing at the RAB Media Centre in the capital on Friday.
A mobile phone believed to have been used to spread the footage was also seized from his possession, he added.
According to RAB, Poran masterminded the June 26 assault to avenge an earlier public humiliation by his elder brother, Fozor Ali.
Quoting locals, RAB said the brothers had quarrelled months ago, ending with Fozor slapping Poran during a village arbitration at Baherchar in Muradnagar.
Seeking revenge, Poran allegedly mobilized a group of villagers through the messaging app Imo.
Around 11:30pm on the night of the incident, Fozor entered the woman's house under the pretext of collecting interest on a Tk50,000 loan he had given her mother.
Twenty minutes later, Poran and several accomplices — identified as Abul Kalam, Onik, Arif, Suman, Ramzan, and eight to ten unidentified others — broke down the door, beat and assaulted the woman, and forced Fozor to join in the abuse.
The attackers then filmed the scene and later posted the video on social media platforms, spreading panic and outrage across the locality, RAB said.
The rape survivor’s family filed a case under the Women and Children Repression Prevention Act and the Pornography Control Act with Muradnagar police station on Sunday.
Law enforcement agencies have so far arrested six suspects, including the survivor’s suspected rapist, Fozor.
During primary interrogation, Poran admitted to planning the attack and directing others to record and circulate the footage as retaliation against his brother, RAB claimed.
He is being turned over to Muradnagar police, while efforts continue to arrest the remaining suspects, the RAB official added.
