The accused, Shantilal Jain, was tracked down from his mobile call records subsequently and arrested.
According to police, Jain was travelling with bullion trader Prakash Kakrecha from Ratlam to Manawar last night in the latter's car.
Kakrecha was carrying gold with him.
When he failed to reach Manawar as scheduled, Kakrecha's relatives became suspicious, said Dhar Superintendent of Police Bhagwant Singh Chouhan.
Jain allegedly told police after the arrest that he gave sedative-laced cold drinks to Prakash and his driver Rajesh Patidar, and went on to strangulate them. He dumped the bodies near Gujri village, before driving off with the gold.