Sri Lanka does not see any need to re-open talks on a contentious island ceded to it by New Delhi 50 years ago, the foreign minister has said, after the low-key territorial squabble turned into a hot-button election issue in India.

The party of Prime Minister Narendra Modi, who is expected to win general elections that start on April 19, has flagged the issue of Indian fishermen discontented after a 1976 pact between the neighbours barred them from the waters around the island.

"This is a problem discussed and resolved 50 years ago and there is no necessity to have further discussions on this," Sri Lankan Foreign Minister Ali Sabry told the domestic Hiru television channel on Wednesday.

"I don’t think it will come up," he said, adding that no one had yet raised the question of a change in the status of the island, located 33 km (21 miles) off India's coast in the Palk Strait that divides the neighbours.

His comments came after Modi's Bharatiya Janata Party made the 285-acre (115-hectare) island an election campaign issue by accusing the opposition Congress party of having "callously" given it away.

The BJP seeks to make election inroads in the coastal state of Tamil Nadu facing the island after failing to win any of the southern state's 39 seats in India's 545-member parliament in the last election.

Tamil Nadu goes to the polls on April 19 in the first of seven rounds of voting set to end on June 1.

India ceded the island to Sri Lanka in 1974, followed by the pact on the fishermen in 1976, but unhappiness over the transfer and the abridged rights spurred two as yet unresolved Supreme Court challenges in the last 20 years.

The fishermen of both countries have occasionally violated the pact on the waters around the uninhabited island, called Katchatheevu.

On Monday, Indian Foreign Minister Subrahmanyam Jaishankar said Sri Lanka had detained more than 6,000 Indian fishermen and 1,175 fishing vessels over the last 20 years, following the no-fishing pact.