Two people have been arrested andtwo are on the run for allegedly killing a person and cremating him with the help of a fake certificate that ruled it as a natural death, police said on Friday.On December 20, Crime Branch Unit VIII got a tip-off that one Mahesh Patel (35), a resident of Madh Marve in Malad, was cremated without any intimation to authorities."We were told he was cremated after a fake certificate stating it was a natural death was procured. Our probe found that Patel's wife was in love with one Arup Sarveshwar Das. An auto driver Sagar Sharma known to them arranged for sleeping pills. After Patel did not die despite being given several pills, Das smothered him with a pillow," the official said.They procured a certificate from a local doctor, who passed it as a case of natural death, and carried out Patel's last rites."Das and auto driver Sharma have been arrested. Efforts are on to nab Patel's wife and the local doctor," he added.