India, July 19 -- Late former Tamil Nadu chief minister M Karunanidhi's eldest son MK Muthu passed away in Chennai at the age of 77, CM MK Stalin announced on Saturday, July 19.

MK Muthu, the brother of Tamil Nadu CM MK Stalin, was born to Karunanidhi's first wife, Padmavathi.

Sharing the news, MK Stalin wrote on X that his brother's passing struck him like a "thunderbolt".

"The news of the passing of my beloved elder brother, MK Muthu, the eldest child of the Muthamizh Arignar Kalaignar family, struck me like a thunderbolt this morning. The sorrow of losing my dear brother, who showed me affection equivalent to that of a mother and father, torments me," Tamil Nadu chief minister MK Stalin wrote on X.

"Our father, Muthuvelar, named hi...