The police said the Trinamool worker was killed while another person was injured when miscreants attacked them with bombs and other weapons at Palaspur under jalangi block of the district.
Police said the murder occurred over an altercation over the control of ferry services in the area.
Soon after the killing, Trinamool all India general secretary Mukul Roy claimed the 28-year-old Trinamool worker "has been murdered in cold blood within 24 hours of transfer of the SP in the district".
"The Election Commission has to bear the responsibility of the murder of the Trinamool worker in Murshidabad," he said.
Roy also demanded the arrest of the state Congress president and union minister Adhir Chowdhury for the murder.
"The supporters of Adhir Chowdhury, bolstered by EC's decision to transfer the SP, have murdered the Trinamool worker," said Roy.
Murshidabad SP Humayun Kabir was one of the seven officers removed from poll duty by the Election Commission Monday.
Angry over the EC order, Chief Minister Mamata Banerjee initially said her government would not remove a "single official" and dared the poll panel to put her in jail.
However, on Tuesday Banerjee relented and agreed to carry out the order, continued to attack the EC.