The boats have been brought to Vizhinjam here on Sunday for a detailed interrogation by all security agencies concerned, it said.
The fishing vessels, intercepted by Coast Guard Ship ''Varaha'' on Saturday, are believed to be of Sri Lankan origin, they said.
After four days at sea the boat’s engine failed, and those on board had run out of food and water, Srivastava said. Many were ill and suffering from extreme dehydration by the time they were rescued.
Prime Minister Narendra Modi on Monday greeted the Indian Coast Guard on its foundation day, saying it was courageously ensuring the country's seas were safe.
The Sri Lankan Coast Guard arrested three fishermen from Thanjavur on charges of crossing the International Maritime Boundary Line (IMBL) early on Friday.