Mathai Chacko died on 13 October 2006 at the age of 47 at Lake Shore Hospital in Kochi due to leukaemia.
This sparked controversy as Mathai Chacko was known to be non-religious and a follower of Communist ideology.
Following this, Pinarayi Vijayan who was then the state secretary of the communist party made the infamous remark describing the bishop as a "wretched creature".
He had said, "Whoever he may be, the person who said that the late Mathai Chacko, who led the pious life of a Communist, had voluntarily accepted the last communion from a priest is only telling a blatant lie, and he is nothing but a wretched creature".
Later, the Syro-Malabar Catholic Church protested against the CPI(M) leadership for the comments against the bishop.