Jail official claims Kishan was severely ill and exact cause of death will be determined after postmortem examination.
An Indian fisherman arrested over a year ago for straying into Pakistani waters died in prison in Karachi on Tuesday after an illness, a senior jail official said.
The man, named by jail officials as Kishan and aged about 50, died in Landhi jail hospital, where he was being held with more than 150 other Indian fishermen.
India and Pakistan frequently arrest fishermen for violating territorial waters, though the Arabian Sea border is poorly defined and many fishing boats lack the technology needed to be certain of their precise location.
Many of them languish in jail for years even after serving their term, as poor diplomatic ties between the two archrivals mean fulfilling official requirements can take a long time.
“He was admitted at the jail hospital for about a month complaining of a severe cough, vomiting, and pain in the abdomen,” said Sunil Shah, the chief of Landhi jail. “We would know the exact cause of death after the post mortem report comes up.”