Shibu, a fisherman from Pallipuram area near Cherthala in the district, had gone to sleep last night, but did not wake up this morning.
Police said Shibu suffered a minor injury in the clash between CPI(M) and BJP activists. He was admitted to a hospital for treatment and discharged a day later.
Noticing that Sibhu remained motionless despite being roused, he was rushed to a hospital where he was declared brought dead, police said, adding, the cause of death would be known only after post-mortem.