Indonesia's navy says items have been found from a missing submarine, indicating the vessel with 53 crew members has sunk with no hope of finding survivors. Navy Chief Yudo Margono said rescuers found several items including parts of a torpedo straightener, a grease bottle believed to be used to oil the periscope and prayer rugs from the submarine.

"With the authentic evidence we found believed to be from the submarine, we have now moved from the 'sub missing' phase to 'sub sunk'," Admiral Margono said at a press conference in Bali where the found items were displayed.

Officials said oxygen supply for its 53 crew ran out early on Saturday and there was no hope of finding any survivors.The Indonesian navy chief of staff said a scan had detected the submarine at 850 metres, well beyond its survivable limits.

The submarine, which disappeared as it prepared to conduct a torpedo drill, is designed to withstand a depth of up to 500 metres. Earlier, an Australian sonar-equipped frigate with a helicopter and a US reconnaissance plane joined the hunt, while Singaporean and Malaysian ships have also joined the search.

Indonesia military spokesperson Djawara Whimbo said Indonesia's hydrographic vessel was still unable to detect an unidentified object exhibiting high magnetism that was earlier detected located at a depth of 50 to 100 metres. There had been no signs of life from the submarine since it went missing, but family members held out hope that the massive search effort would find the vessel in time.

Indonesian President Joko Widodo had ordered all-out efforts to locate the submarine and asked Indonesians to pray for the crew's safe return.The search focused on an area near the starting position of its last dive where an oil slick was found but there was no conclusive evidence so far the oil slick was from the sub.

Margono, the navy chief, had said oil could have spilled from a crack in the submarine's fuel tank or the crew could have released fuel and fluids to reduce the vessel's weight so it could surface. The navy however, believes the submarine sank to a depth of 600-700 metres, much deeper than its collapse depth of 200 metres, at which water pressure would be greater than the hull could withstand.

The cause of the disappearance is still uncertain, but the navy has said an electrical failure could have left the submarine unable to execute emergency procedures to resurface. The German-built diesel-powered KRI Nanggala 402 has been in service in Indonesia since 1981 and was carrying 49 crew members and three gunners as well as its commander, the Indonesian Defense Ministry said.