Terzi told ambassador Debabrata Saha that the incarceration of the two soldiers in a prison in Thiruvananthapuram in the southern state of Kerala ordered by a judge on Monday was "unacceptable", a ministry spokesman said.
Even the preferential treatment afforded to the two men, Massimiliano Latorre and Salvatore Girone, who are currently being housed in a separate structure within the prison was "not satisfactory", Terzi told the diplomat.
The two were deployed as security guards on an Italian oil tanker and they were arrested in Kerala last month after allegedly killing the two fishermen who were on a boat that was apparently mistaken for a pirate vessel. Terzi reportedly told the ambassador that Italy "does not recognise the legitimacy" of the legal case in India "due to the absence of jurisdiction."
There is growing outrage over the arrests in Italy with the government saying the incident took place in international waters and involved an Italian-flagged vessel and should therefore be investigated in Italy.
Terzi earlier said the arrests of the two military personnel represented an infringement of Italian sovereignty. His handling of the case has been heavily criticised by foreign policy commentators and right-wing political forces. India argues that the incident took place in Indian waters and an appeal lodged by Italy to have the case thrown out is pending in Kerala.