KOHIMA: Amid the electioneering heat and dust three top CMO officials in Nagaland feel the heat of extortion charges. The trio is facing NIA interrogation in Guwahati on Thursday. According to sources NIA has issued notices to the officials to appear in the Guwahati based office to be questioned on the allegations of extortion. NIA Deputy Superintendent of Police Jasveer Singh who happens to be the Chief Investigating Officer is all set to interrogate the trio on Thursday. The investigation agency has been probing the charges since 2016. Some incriminating documents have suggested their involvement in the extortion cases in the state.