Katchatheevu is an islet in the Palk Straits which was ceded to Sri Lanka by India under an agreement in 1974.
Referring to the reported remarks made by the Lankan President, where he had not named any country but mentioned about a particular state in a neighbouring northern nation, Karunanidhi said the former's speech indicated that Tamil Nadu fishermen could face the brunt.
"His remarks indicate that there could be legal provisions wherein Tamil Nadu fishermen could be sentenced to 20 years in jail if caught fishing in Sri Lankan waters," the DMK chief, whose party is a key constituent of the ruling UPA, said, replying to a set of questions in party mouthpiece 'Murasoli.'
"Therefore the Central government must take steps and safeguard Tamil Nadu fishermen," he said.