Family sources said he had been sufferig from old age related ailments for some days.
Muthu, a bachelor, represented Oulgaret constituency as DMK nominee from 1969 to 1974 when the DMK-CPI alliance formed the government.
He shifted his allegiance to MDMK a few years ago.
MDMK founder leader Vaiko paid his last respects by placing a wreath on his body.