"I request your personal intervention to issue directions to the External Affairs Ministry to take up the matter with the Sri Lankan authorities and secure the immediate release of our 64 fishermen and 77 fishing boats still in Sri Lankan custody," she said in a letter to Modi.
"May I request you to accord the highest priority to this issue," she said.
In the first incident, nine fishermen on board a mechanised fishing boat, from the Rameswaram fishing base, were apprehended and taken to Thalaimannar in the neighbouring country.
Fifteen fishermen on board two boats and five others on board another boat from Threspuram in Tuticorin District were taken into custody and taken to Kalpitiya, in Sri Lanka, she said.
"The right to life and livelihood of Tamil Nadu fishermen who carry on fishing in the traditional waters of the Palk Bay is being infringed upon by the Sri Lankan Navy's recurrent actions of apprehension, attack and harassment of the innocent fishermen," she said.