The wreckage of a US Navy submarine that sank the most Japanese warships during World War Two has been found in the South China Sea, some 80 years after it was sunk by enemy forces.

The USS Harder was found 3,000ft (914m) below water off the Philippines' northern island of Luzon.

The Harder was sunk in battle on 29 August 1944, along with its crew of 79 men.

In one of its final war patrols, it sank three Japanese destroyers and heavily damaged two others over four days, according to the US Navy's History and Heritage Command (NHHC).

This forced the Japanese to change their battle plans and delay their carrier force, contributing to their defeat.

“Harder was lost in the course of victory. We must not forget that victory has a price, as does freedom,” said Samuel J. Cox, a retired US admiral who heads the NHHC.

The Philippines was one of the main Pacific battlegrounds of World War Two, as the US fought to retake its former colony from the Japanese Imperial Army.

Waters in and around the archipelago have served as the resting place of famed World War Two battleships.

In 2015, US billionaire Paul Allen located the wreck of the Musashi, one of the two largest Japanese warships ever built, in the Philippines' Sibuyan Sea.

The Harder, which sailed under the motto of "Hit 'em harder', was found by the Lost 52 project, which aims to find the 52 US submarines lost during World War Two. It was found sitting upright on its keel or spine, and relatively intact, the US Navy said.

The submarine and its crew were later awarded the Presidential Unit Citation for its service during the war. The honour recognises extraordinary heroism in action.

Its skipper, Commander Sam Dealey, was posthumously awarded the US's highest military decoration, the Medal of Honor.