Judge of Judicial Magistrate Court-1 Md Rashed passed the order after police produced Abul Hossain before the court on expiry of a three-day remand.
The same court granted the remand on Thursday after investigation of the case Arabinda Sarker sought a seven-day remand for interrogation.
Earlier on Wednesday, police arrested Abul Hossain, a local industrialist and owner of Shimla Hospital and Diagnostic Centre.
Subarna Akhter Nodi, 32, district correspondent of private channel Ananda TV, and editor of Daily Jagroto Bangla, an online news portal, was hacked to death on Tuesday by a group of miscreants while returning home from her workplace in the district town.
Nodi's mother filed a case with Sadar Police Station against 6-7 people, including Abul Hossain and his son Razib Hossain, also former husband of Nodi, over the killing.