A Court of Inquiry has been ordered. [Representational Image]Wikimedia Commons

The families of those on board the Indian Air Force's AN-32 aircraft have been told that their relatives have been "presumed dead."

The families have been finally informed that chances of the passengers surviving the accident seem "unlikely" and that they could proceed with the insurance and other administrative formalities.

The letter, titled Presumption of Demise, also states that a Court of Inquiry was conducted by the Air Force station at Sulur to examine the available evidence and establish the possibilities of survival of the aircrew and passengers. It was concluded that "it is unlikely that the missing personnel on board the ill-fated aircraft would have survived the accident."

The letter added that the conclusion was arrived at after "careful scrutiny of the circumstantial evidence available and in light of existence search and rescue operation carried out."

The IAF has also requested family members to sign the "certificate of presumption of death" so that  the authorities could begin with the legal proceedings for compensation, India Today reported.

The IAF added that it had made all efforts in trying to locate the aircraft and the missing personnel. "No fewer than 201 search and rescue sorties, using all suitable aircraft at our disposal were undertaken. Approximately 2,17,800 square Nautical Miles (Sq Nm) has been covered multiple number of times by these aircraft," the letter stated.

Data from international emergency response teams and satellites from USA also did not help in getting any concrete information about the missing aircraft, it said.

However, the search operation for the aircraft is still on with Remotely Operated vessels scouring the seabed for objects of interest.

The IAF AN-32 aircraft, travelling from Chennai to Port Blair with 29 people on board, including eight civilians and six crew members, went missing on July 22 this year. The aircraft, which had taken off from the Tambaram Air Base in Chennai, went off radar shortly after, without giving a distress signal.

Search operations for the missing plane have been going on for almost two months, with 17 ships, a submarine and 23 aircraft deployed in the mission.