A former MLA of AIADMK, O.S. Amarnath, passed away here on Sunday. He was 66. Amarnath, who had represented the erstwhile Madurai East Assembly constituency in 1991-96, was not well and was admitted to a private hospital where he breathed his last. Amarnath was also the deputy secretary of party Madurai district Amma Peravai. He is survived by his wife Rasheela and son O.S.A. Aravind.