According to the prosecution, Sivamurthy, 47, who runs a knitwear export firm hailing from Karumarampalayam in Tirupur, had gone missing on June 25, 2018. His three mobile phones were also switched off.
Police registered a case and arrested Vimal, 35, Gauthaman, 22 and Manikandan alias Manibarathi, 22, all hailing from Coimbatore on June 27. They confessed to have kidnapped and killed Sivamurthy by strangulating while demanding a ransom of Rs 50 lakh.
Police also arrested Murthy, 35. Vimal, who was known to the deceased, had conceived the plan.
Tirupur Principal District Court Judge Sornam J Natarajan awarded the 4 accused life term for murder, 10 years for kidnap, 10 years for extortion and 3 years for destroying evidences.