Ansarullah Bangla Team (ABT) chief Jasimuddin Rahmani was released for three hours on parole from Kashimpur Central Jail, following the death of his elder sister.
His elder sister Momtaz Begum, 65, died on Wednesday.
The parole, granted from 9am to 12pm, came after an application was submitted by one Nazrul Islam.
According to police sources, Rahmani was transported by helicopter, with the assistance of Gazipur Metropolitan Police, to the Circuit House ground in Barguna, where his relatives and followers were preparing for the funeral.
Upon arrival, Rahmani performed ablution, spoke with his family members, and then led the funeral prayer for his sister.
After the namaz-e-janaza, he was returned to Kashimpur Central Jail by helicopter.