A local Congress leader died of cardiac arrest at a counting center at Sehore in Madhya Pradesh Thursday.
Ratan Singh Thakur, district Congress chief, suffered a heart attack around 10 am as counting of votes for the Lok Sabha polls was underway.
He was taken to the district hospital but could not be saved, a Congress leader said.
Madhya Pradesh Chief Minister Kamal Nath condoled the death, saying that Ratan Singh Thakur was an "energetic, hard-working and friendly person".
Former chief minister Shivraj Singh Chouhan also paid tributes to Mr Thakur.