Suman Mia was killed in the Bakharnagar area of Alokbali Union in Narsingdi Sadar.
The incident was described as occurring on Thursday, although the accounts differ on whether it was in the evening or at night.
He was taken to Narsingdi Sadar Hospital after the attack, where a doctor declared him dead.
Relatives gave conflicting accounts of the assault, including whether he was attacked with sharp weapons or shot.
One family account said a group of 10 to 15 armed people stopped him at Bakharnagar market and attacked him with sharp weapons.
Another family account said armed people seized him near a riverbank, took him to a tea stall and shot him.
His age was given as 30 in one account and 23 in another.
Police said a local dispute was the preliminary suspected context for the killing and that they had begun an investigation.
Relatives alleged that the killing followed a prior dispute, but did not publicly identify any specific suspect.
A local BNP leader alleged that political rivalry was involved, an assertion not established by the police statements.