According to news agency PTI, the police said that the eight-minute long conversation, which was circulated on social media, was between Mohammed Rafiq, who has completed a jail term in the 1998 blast case and lives in Kuniyamuthur in Coimbatore, and a transport contractor Prakash.
"The conversation was mainly related to finances about vehicles. But suddenly the blast convict was heard saying 'we have decided to eliminate (Prime Minister) Modi, as we were the ones who had planted bombs when (LK) Advani visited the city in 1998," the police said.
Coimbatore suffered a series of bomb blasts in February 1998 in which 58 people were killed and property worth crores was destroyed.
Coimbatore Police formed special teams to investigate the recorded conversation and verify the genuineness of the persons in it, the police said in a press release seen by news agency PTI.
The man has been arrested based on the conversation, it said.
Get Breaking news, live coverage, and Latest News from India and around the world on NDTV.com. Catch all the Live TV action on NDTV 24x7 and NDTV India. Like us on Facebook or follow us on Twitter and Instagram for latest news and live news updates.