Australian World War II prisoner of war Charles Edwards has returned to the Japanese prison camp where he was held for the last months of the war, and witnessed the nuclear bombing of Hiroshima.

Charles Edwards was taken prisoner at Parit Sulong in Malaysia in 1942 - one of about 140,000 allied soldiers captured in South East Asia and the Pacific throughout the war.

Sorry, this video has expired Charles Edwards describes the nuclear bombing of Hiroshima ( Kate Arnott )

For decades, Mr Edwards stayed silent about his ordeal in jails, prison camps and time on the Thai-Burma railway, where he nearly starved to death and endured life-threatening illnesses and extreme brutality.

"When we came home we were told not to talk about it, and we didn't," he said.

"Until some years later, I was talking to Sir Weary Dunlop and he went out and gave lectures all over the place about the horrors and atrocities and he said, 'Why not go out and tell them. I appeal to you all to go out and tell people', so I did just that.

"When I gave a lecture in the museum, one of the students was a Japanese, and he came to me with tears in his eyes and he said, 'you know, we have never ever been told of the brutality dealt out to you prisoners'."

Since World War II, students in Japan have regularly been taught about the destruction caused by the atomic bombs dropped on Hiroshima and Nagasaki by the United States - but they have been told little about Japan's wartime atrocities, including the treatment of POWs.

Eager to find out more, Tokyo resident and associate professor Miyo Sakuma joined the Prisoner of War Research Network of Japan, an organisation formed 10 years ago with the aim of passing on information about POWs to future generations, to learn from past mistakes.

Last month, her path crossed with Mr Edwards, when the 95-year-old returned to Japan for the first time since the war.

"[Charles Edwards] is a great guy," she said. "I really appreciate for ex-POWs like Mr Edwards for sharing their stories.

"I felt he's very resilient to come to Japan after experiencing these bad things, so I really respect him."

Travelling with three fellow ex-POWs and his granddaughter, Charles Edwards's trip was funded by the Japanese government as part of its Friendship Building program.

"He said it was the greatest day of his life to shake hands with his former enemies, who were now his friends." ( Supplied: Carolyn Archibald )

They visited the site of the Ohama prison camp - 125 kilometres from Hiroshima - where Mr Edwards was held during the final months of the war.

"One of the things about it, another car pulled up and an old man got out," he said.

"He was rather bent up and he introduced himself as one of the guards that had guarded us.

"He said it was the greatest day of his life to shake hands with two of his former enemies, who were now his friends."

Mr Edwards's granddaughter Carolyn Archibald says her grandfather really wanted to go back to the prison camp site.

"Being at the Ohama prison camp, I think everybody was trying to make a positive experience about the return," she said.

"There was lots of laughter and lots of smiles."

The camp also brought back memories of the moment Charles and fellow prisoner Burt Kelly witnessed something they would never forget.

"All at once, without any sound, the most beautiful white light appeared, it seemed to come in both doors, met Burt's body, flowed up his body met at the top of his head and formed a silver halo," he said.

"Then all at once the vision disappeared.

"Burt was still there - I was still here, so we walked out the east door and we were hit by a wave of hot air, then we looked away to east and just rising above the horizon was a mushroom-shaped cloud.

"It was a new type of bomb the Americans had just dropped on the city of Hiroshima."

For Ms Archibald, it was also a moment never to be forgotten.

"I took away how extraordinary it was to be standing there with him on the spot where he witnessed the white flash of light of the Hiroshima bomb dropping," she said.

The trip to Japan also included many opportunities to meet and share stories with the locals - something Mr Edwards relished.

"The Japanese people were so beautiful, and they still are," he said.

"They're courteous, kind, they laugh a lot - so my opinion of the Japanese people has never altered.

"It was only the IJA - the Imperial Japanese Army - that were brutal to us."

Associate Professor Sakuma says the Japanese government has been running the Friendship Building program for the past three years, and it has also offered formal apologies to ex-POWs.

"These things should have been done earlier - but this is a huge step," he said.

"This is the result of a concerted effort by civilians, journalists, researchers and some politicians who had helped ex-POWs come to Japan way before this friendship program started."

At 95, the trip gave Mr Edwards a sense of closure.

"It sort of put an end to all my wartime experiences," he said.