Senior Judicial Magistrate SM Rajibul Hasan of Kishoreganj Judicial Court-1 has passed the order in a crowded courtroom.
ASP Rajib Kumar Dev, investigation officer of the case, produced Sirajuddin Bhuiyan to the court seeking 10 days remand.
Earlier, elite force Rapid Action Battalion arrested Sirajuddin from Bhairab Railway Station around 6am on Saturday, Bhairab RAB 9 Assistant Superintendent Manjur Rahman said.
Sirajuddin is the uncle in-law of Habibur Rashid, alias Sohel Rana, who had plotted the daring haul and managed all the accessories for the heist.
Sirajuddin hails from Charpumdi village under Hossainpur upazila of the district. He was arrested a month after more than Tk16 crore was looted from the branch, he added.
Investigation officer of the case, Mymensingh RAB 14 personal Rajib Kumar Dev, said; “He is the mastermind. He influenced Sohel for the heist.”
Detained Sohel Rana said he owed Tk5 lakh to Siraj. Unable to refund the money, Siraj plotted the haul and taught Sohel how to tunnel into the bank.
Officials discovered the bank heist on January 26 and found over Tk16 crore missing from its vault. Two days later, Sohel Rana and his affiliate Motahar were held from Dhaka with Tk1, 61, 95, 664 of the stolen money.
Later, the remaining Tk2.5 lakh was found when Sohel's wife Maliha Akhtar from the capital.
The two robbers named several employees of the Sonali Bank who said to have aided in the heist.
On February 3, the High Court ordered the investigation of the burglary case to be transferred to RAB in response to a petition fearing police failure.
Nearly three weeks after the order, elite force RAB has managed to arrest the plotter of the Sonali Bank burglary case.
