Md Sahadat Hossain was arrested by a special task force after the two ABT terrorists - Samsad Mia and Rizaul Islam - provided information to the police on his dealings with them, the police officer said.
Shahadat is suspected to have been helping several others in crossing the porous India-Bangladesh border, he said.
"It appears that Sahadat has helped many from Bangladesh to cross the border. He used to do this in exchange for money. We are grilling him to find out how many people he has helped in crossing the border," the police officer said.
On Tuesday, the STF arrested Mia and Islam with arms supplier Monotosh Dey and seized several fake documents and arms from them. They are suspected to be behind the killing of secular bloggers and writers in Bangladesh.
Disclaimer: No Business Standard Journalist was involved in creation of this content