Rapid Action Battalion (RAB) arrested former Sirajganj-3 Awami League lawmaker Md Abdul Aziz from the city's Kalabagan area on Monday night.
RAB media wing officer Senior Assistant Police Super Muttajul Islam confirmed BSS of the arrest.
Aziz was accused in multiple cases linked to the attacks on the July-August protest rally.
He will be produced before the court on Tuesday.
