One of the most extraordinary stories from World War II, paradoxically, is one of the least known: the sinking of the Lisbon Maru.

This was the scene, in the ocean waters around a remote island off the Chinese coast: “On October 2, 1942, the Lisbon Maru, a Japanese freighter carrying 1,816 British prisoners of war, was torpedoed in the East China Sea by an unwitting American submarine. As the ship sank, Japanese forces battened down the British POWs in the holds, leaving them to die. Some prisoners broke free at the last moment; 384 were rescued by local Chinese fishermen from the island Zhoushan, while 828 perished.”

The wreck of the Lisbon Maru and the story behind its sinking might never have been known beyond family members of the dead and survivors, were it not for Fang Li. The Chinese geophysicist, marine technologist, robot designer, and filmmaker challenged himself to locate the sunken vessel and resurface the tale of villainy and heroism behind it.

“I heard this story 10 years ago when I was shooting a feature film on the island [of Zhoushan] with a young director, popular writer in China, and he and I were sitting on an upper deck on a yacht. It would take two hours from shore to get to this offshore island, tiny island,” Fang recalled at a recent Q&A in Los Angeles. “This [yacht] captain was telling me 75 years ago there was a big Japanese vessel torpedoed by an American submarine… and Chinese fishermen ran to the rescue. I was totally surprised because I’m a history buff. I know all those general stories — never heard about this big story.”

Fang continued, “So, when I returned to the shore, I verified it with a local official, and he said, ‘Yes, it is true.’ And, also, everybody told me nobody ever found the shipwreck. That caused a big curiosity for me because I’m a volunteer in China for any rescue on the water.”

Fang, as a geophysicist, set about identifying the location of the sunken Lisbon Maru.

“Why nobody else found the shipwreck is because Japanese records were wrong, because at that time they looked at the stars [for navigation]. Today, we look at the satellites. The accuracy is so different. Where we found the shipwreck and where Japanese records [said it would be] — the offset is 36 kilometers, too far away. That’s why I swept the whole area of the sea floor.”

It took two years, but using magnetometers, underwater robots and other equipment, he located the shipwreck and verified it was the long-lost Lisbon Maru. Then came the next challenge – tracking down families with a connection to the POWs who had been transported on that ship.

“I heavily advertised in the Sunday Times, Daily Telegraph, The Guardian — I found 80 plus relatives of POW families,” Fang explained. “Plus, I succeeded in finding another POW still alive in Canada.”

The result of Fang’s investigations can be seen in the Oscar-contending documentary The Sinking of the Lisbon Maru. He uses animation to show what happened as the Lisbon Maru’s fate was sealed.

“I also have a very strong mechanical engineering background,” he said. “I analyzed every moment, what happened starting from the torpedo hitting the stern and how the water goes through the tunnel into the boiler room… water [leaked] into hold number 3, every little detail.”

As the film shows, after the ship was hit and began to sink, Japanese military sealed in the POWs, intending for them to die as the vessel went under. The prisoners managed to break out of their hold, and many were able to fling themselves into the water. But their ordeal continued as Japanese forces fired upon them as they bobbed in the waves.

Eventually, Chinese fishermen came to the aid of the imperiled men and plucked many from the sea and took them to shore.

“They fed British POWs over two nights. They gave them all their food,” Fang said, “And many old women and housewives, they [gathered up] clothes, even their blankets they cut into pieces to wrap POW’s feet.”

Fang added, “You go to this village today, the villagers, they don’t think it’s a big deal. They don’t think their [ancestor] is a hero.”

The Sinking of the Lisbon Maru was chosen as China’s official selection for Best International Film at the Oscars. But later, it was ruled ineligible because the Academy judged more than half of its dialogue was in English.

“I was really surprised twice,” Fang said. “I was surprised the China committee of selection picked my film… This is the first surprise; second surprise, the committee telling me the English dialogue is over 50 percent. I said ‘b*llsh*t’ because the dialogue is only 40 percent. The other [part] is voiceover when the English people are reading the documentation, and they’re also reading letters [from loved ones who were POWs]. That’s not dialogue. They counted that as dialogue, very unfortunately.”

As a result, the film doesn’t appear in Best International Feature competition, but it has qualified for consideration as Best Documentary Feature.

“I don’t do the film for Oscar,” Fang commented. “I do film for the audience, for the family of [POWs and rescuers].

Fang added, “It is really a personal commitment to everyone. I feel I’m part of them because I cannot forget at all.”