He was arrested at BIRDEM Hospital around midnight on Friday, Adabar Police Station OC Gazi Ruhul Imam told bdnews24.com.
He walked out of Feni jail after the High Court gave him a six-month bail on July 17 for health issues.
Later the Appellate Division scrapped the bail and told him to surrender in a lower court.
Minar ignored the order and a warrant was issued for him, on which he was arrested on Friday.
Ekram, former Phulgazi Upazila chairman, was killed in a daylight attack on May 20 in Feni town.
His brother filed a case the same day naming Minar as the prime suspect.
Minar was arrested on May 27 in Dhaka and had been kept at the Feni jail since June 4.
He was treated at a Dhaka hospital as his health had deteriorated.
The BNP leader had heart and other ailments.