The Defence Research and Development Organisation (DRDO) is investigating the reported satellite phone signals traced from a village near Kangeyam in nearby Tirupur district.
The signals were picked up from a village near Kunnathur by INS Parundu, an Indian Naval air station located near Uchipuli in Ramanathapuram district, and officials alerted DRDO, police said.
A team from DRDO is at Kunnathur to trace those using the satellite phone, police said, adding use of such phones is banned in India.