Avinash Bali, the key witness in the 2011 murders of Keenan Santos and Reuben Fernandez, was allegedly killed by his friend Nilesh Shukla over some personal dispute, the police said on Sunday as they announced arrests of three persons in the case. A personal cum financial dispute between Bali (40) and Shukla (38), the prime accused in the case, seems to be the cause behind the crime. Bali's body, with injury marks on his head and private parts, was found lying in his shop in the MIDC area of Suburban Andheri.