A key accused in the killing of Special Sub-Inspector Wilson in Kanyakumari district was arrested here on Saturday, police said.
Sheikh Dawood, who was allegedly financing the killers of theI, was staying in the district under the guise of a fisherman when he was held, police added.
He allegedly financed theI's killing, police said adding Dawood had managed to escape when three men with suspected links to the ISIS and connected to cases being probed by the National Investigation Agency were arrested in Devipattinam in the district on January 22.
He was reportedly funding B Mohammed Ali and Mohammed Amir, who were held for suspected ISIS links.
Dawood was at a gymnasium here when he was arrested based on a tip-off, police said.
Two men-Abdul Shameem (29) and Taufeeq (27)- hailing from Thiruvithancode near Nagercoil, had shot at Wilson using a pistol and stabbed him when he was on duty at the Kaliyakavilai checkpoint on the border with Kerala on January 8.
The two were picked up from Udupi Railway station in Karnataka on January 14 and have been lodged in the Palayamkottai central prison.