Murder of Thota Rama Rao (48) alias Oil Ramu, a waste oil dealer and YSRC leader, was due to business rivalry say the police and it also looks like a case of a supari gang changing sides to kill the person who had initially engaged it, after he failed to pay the amount in full. Five persons were arrested by the City Police on Thursday in connection with the murder and police said business rivalry between Ramu and another waste oil trader M. Srinivasa Reddy alias Bunk Reddy, was the cause for the murder.