The deceased was identified as Manirul Islam, 35, son of Ali Box of Barandali village in the upazila.
Quoting local people police said Manirul had an altercation with the supporters of Reza Hasan Sabuj over the issue at Saraskati Bazar in the upazila on Tuesday.
At one stage, a clash ensued among them, leaving four people including Manirul injured.
Later, they were taken to Keshabpur Upazila Health Complex and Manirul was shifted to Khulna Medical College and Hospital where he succumbed to his injuries on Wednesday morning.
Shamim Hossain, sub-inspector of Chingra Police camp, said a case was filed with Keshabpur Police Station in this connection, reports UNB.
Police also arrested three people in this connection.