An IPS officer has gone missing from Tippi in West Kameng district of Arunachal Pradesh when he was on his way to Tawang from Itanagar. Superintendent of Police of the Special Investigation Cell in the state police M S Chauhan went missing from Tippi yesterday at around 2.30 PM when he, along with two of his subordinate staff, was going to Tawang. West Kameng SP T T Lama said there was no information of his whereabouts since then. The Gauhati High Court had appointed Chauhan as the special investigating officer of the multi-crore PDS scam in Arunachal Pradesh in 2008.