Saravana Suresh, nephew of MDMK leader Vaiko, who had set himself on fire over the Cauvery water dispute, died on Saturday.
Announcing his death in a local hospital where he was admitted, Vaiko appealed to the youth not to commit self-immolation. He said his entire family was shattered by the development.
Suresh, who is the son of the brother of Vaiko's wife, set himself afire in Virudhunagar after feeling disturbed over the Cauvery water dispute. He was first taken to the Virudhunagar Government Hospital and, later, to a private hospital in Madurai where he was undergoing treatment.
In a statement on Friday, appealed to people to refrain from harming themselves in similar manner, the MDMK leader said Suresh had listened to his speech against Prime Minister Narendra Modi's visit to Chennai on Thursday and had been feeling disturbed ever since.
According to Vaiko, on Friday morning Suresh said he was going for a walk. Later, it was found that he had doused himself with kerosene and set ablaze.
"I have lost hope of his survival. All in my family are suffering... (due to this incident)," Vaiko said.
Vaiko had earlier said that though Saravana was not holding a party post, he had been working for the party for several years.
Tamil Nadu political parties and various other organisations are protesting against the central government for not setting up the Cauvery Management Board (CMB) and Cauvery Water Regulatory Committee (CWRC) as per a Supreme Court order.
The Supreme Court on February 16 reduced Tamil Nadu's share of Cauvery water to 177.25 thousand million cubic feet (TMC) from the earlier 192 TMC granted by a tribunal in 2007, while Karnataka's share of water was increased by 14.75 TMC.
The court also ordered the Centre to set up the CMB within six weeks of its order. But, the government failed to do so within the deadline that ended on March 29.