A team of RAB-1 captured Rafiqul Islam Arman around 12am today, Assistant Superintendent of Police (ASP) Salahuddin told BSS.
With him, a total of nine suspects were captured over the journalist Tuhin murder.
Six were held by the police, and three by the RAB.
Faisal alias Ketu Mizan, mastermind of the murder, his wife Golap, Sumon, Al Amin, Swadhin, Md Shahjalal, Md Faisal Hasan and Shahidul were earlier arrested in this connection.
One of the eight suspects arrested earlier has confessed in court to taking part in the murder.
Shahjalal, 32, from Antapur village in Homna upazila of Cumilla, admitted his involvement before Gazipur Metropolitan Magistrate Court-3 Judge Omar Haider on August 10 last, police said.
The confession was recorded under Section 164 of the Code of Criminal Procedure.
According to police, two separate cases have been filed over the incident - one by Tuhin's elder brother and another by the brother of Badsha Mia, who was injured in the initial attack.
Tuhin, 38, a staff reporter for the daily Protidiner Kagoj, was hacked to death at a tea stall inside Masjid Market at the busy Chandna Chowrasta intersection around 8pm last Thursday, reports BSS.