Police said Maniazhagan (59), who retired as ACP, Tambaram, visited the town to attend a family function.
There was a verbal altercation between Maniazhagan and his relative Manikandan over the sale of the former’s house in Tiruvannamalai during the function.
When the argument became heated, Manikandan assaulted the retired cop and dragged him out of the function venue. An injured Maniazhagan was admitted to the Tiruvannamalai Government Hospital, from where he was shifted to the Rajiv Gandhi Government General Hospital in Chennai. Based on a complaint, Tiruvannamalai taluk police registered a case against Manikandan and two others. Further investigations are under way.