Dhaka Metropolitan Magistrate Md Ziaur Rahman passed the order after the investigation officer of the case sought a five-day fresh remand for further interrogation.
Irfan, suspended councillor of the 30th ward of Dhaka South City Corporation (DSCC), was produced before the court after the end of his three-day remand.
The duo was earlier placed on a three- days remand on October 28.
Lieutenant Wasif Ahmed Khan of Bangladesh Navy filed the case at Dhanmondi Police Station naming four people.
Apart from Haji Selim’s son Irfan and Zahid, the other accused are -- AB Siddique Dipu, 45, and Md Mizanur Rahman, 30. All four are now behind bars.
According to the case statement, a car hit Wasif's motorcycle near Labaid Hospital at Dhanmondi around 7:45pm when he and his wife were returning to their Mohammadpur residence from Nilkhet.
Some people came out of the car and physically assaulted the navy official and verbally abused his wife.
Rab arrested Irfan from his father Haji Selim’s residence on Devdas Lane in Old Dhaka on Monday afternoon. Two firearms, 38 walkie-talkies and liquor were seized from Irfan’s house during the drive.
Meanwhile, the government suspended Irfan from the post of councillor on October 27.
Also read: How the mighty fall: The case of Haji Selim