The former Navy officer was produced before Senior Judicial Magistrate AKM Mohiuddin at Narayanganj on Sunday afternoon.
He is among three former RAB-11 officers accused of abducting and killing Ward-2 Councillor Nazrul Islam and six others in exchange of money last month.
Police sought 10 days to question him.
Rana was arrested from Dhaka Cantonment on Saturday night, a day after his two other colleagues were arrested from the same place.
The other two disgraced officers - Lt Col Tarek Sayeed Mohammad and Maj Arif Hossain - were already sent to 5-day remands on Saturday.
The trio were removed from RAB-11 after the seven men were abducted on Apr 27. They were forced to retire after all their bodies were found floating in the Sitalakhyya River at Bandar Upazila three days later
Rana was the commander of a RAB-11 camp in the Narayanganj old court area.
The slain councillor’s father-in-law claimed that the seven were murdered in this camp.
“The seven were killed in this camp office after the abduction. Evidence will be found if that camp is raided,” Shahidul Islam told reporters in the court complex on Sunday.
The three former RAB officers used to live in an apartment near the Siddhirganj power station, said Islam, insisting that it should be searched.
He also claimed that ASP Rabiul, who is posted at RAB-11, is also involved in the killings and demanded his grilling.
Former naval officer NM Rana, however, denied his involvement.
He pleaded innocence in court, saying the place of the abduction was not under his jurisdiction.
Meanwhile, a Narayanganj court has served a show-cause notice on the investigating officer (IO) Mamunur Rashid Mandal.
He was pulled up for not showing as arrested two former RAB officers, who have been arrested for suspected involvement with the murders.
The IO has been told to explain his action within four days.
Police have been granted four days to grill Mahibullah, the driver of the prime accused Nur Hossain.
Detective police have also questioned Hossain’s so-called ‘girlfriend’, Jannatul Ferdous Neela, a city councillor from reserved women seat of Narayanganj City Corporation.
