Coimbatore: A mother-son duo and their accomplice were arrested on Thursday for murdering a man and setting the body ablaze at a stone quarry near Veerapandi in Tirupur city on last Saturday (July 17). An investigation officer said 46-year-old Murugeswari, of Thiruvalluvar Nagar at Veerapandi, was in an illicit affair with 36-year-old Santhoshkumar, who had lent her Rs 70,000 a few months ago. “When he demanded the amount back, she refused to repay him. The woman hatched a conspiracy with her son Arockiyadass and his friend Balasubramanian, both aged 21 years, to finish off Santhoshkumar,” the officer said. On July 17, he said, the two men attacked Santhoshkumar with an iron rod, dragged him to the stone quarry at Kallangadu and set him ablaze. On July 18, Santhoshkumar’s wife lodged a complaint with the Veerapandi police, who registered a missing person case and initiated inquiry. “We found that he was murdered by Arockiyadass and Balasubramanian, who have confessed to the crime when we picked them up for questioning,” the officer said. The charred body was recovered from the stone quarry on Thursday and postmortem was done on the spot. Police have registered a first information report against the trio under Sections 302 (punishment for murder), 201 (causing disappearance of evidence of offence) and 120B (punishment of criminal conspiracy) of the Indian Penal Code and arrested them. They were lodged in jail under judicial custody later in the day.