For 30 years members of Australia's World War II commando Z Special Unit were sworn to secrecy and their heroism unacknowledged.
But recently there has been growing recognition of the specialist reconnaissance and sabotage unit the Australian Army credits as the foundation for the modern Special Air Services Regiment or SAS.
In 1943, in what is regarded by many as the most successful clandestine military operation ever — Operation Jaywick — a team of 14 Z Special Unit commandos paddled into Singapore harbour in kayaks and attached limpet mines to Japanese enemy shipping.
The stealthy raiders sank seven ships or 39,000 tonnes before escaping home to Australia undiscovered.
Over the course of the war, the 70-foot wooden-hulled boat involved in the Jaywick raid, MV Krait, sank more shipping than any other ship in the Australian navy.
Former Z Special operative Douglas Herps said the strain of the missions had been "horrendous".
"They travelled thousands of miles in enemy occupied territory. The men got out of the boat and paddled canoes for hundred miles into Singapore.
"They did their job, got out and found the Krait again after two weeks.
"Think about these men — they did not know if they were going to be picked up.
"The Krait was a little 70-foot boat and it sank more shipping than cruisers with 800 men on board."
He said only the military's top brass knew of the unit's existence.
"The unit was under the control of General Thomas Blamey, the Prime Minister (John) Curtin and Douglas MacArthur, who was the American general in charge of the whole operation," Mr Herps said.
"They were the only people plus a couple of the senior staff in the Australian Army that knew about Z Special Unit.
"We never had any colour patches at all.
"After the war we just let other people talk about it.
"If you talk to a true Z fellow he wouldn't know what his mates did. We just know what we did ourselves and even then I don't like talking about it now."
In a subsequent mission to Jaywick called Operation Rimau, the raiding party was detected by the enemy, hunted down and executed.
Seventeen of Z Special Unit lie in graves at Kranji War Cemetery in Singapore.
In Operation Copper eight men landed on an island off New Guinea to disable enemy guns before the Allied landing.
Discovered by the Japanese, three commandos were captured, tortured and executed.
Four others escaped and fled out to sea, but only one made it home.
Former Z Special Operative Jack Tredrea parachuted into Borneo on March 25, 1945, and spent seven months on the island gathering intelligence.
"We trained on Frasier Island for a year. We had to learn to speak Malay.
"We did our jump into Borneo four months before the invasion to organise the native population.
"We trained 2,000 of them and when the invasion came we had 32 operatives each with their own guerilla force."
"We were guerillas, so all our work was hit and run.
"If we couldn't kill everyone in a patrol, we killed as many as we could and then vanished back into the jungles again.
"A lot of the four-man, six-man, eight-man operations were done from those Japanese fishing boats where they infiltrated an island operated by the Japanese.
"They were were picked up at a later date.
"Quite a few failed but that was the name of the game."
Z Special Unit was assembled from mainly Australian, British, Dutch and New Zealand members but it also recruited fighters of Timorese and Indonesian heritage.
WWII historian and former naval officer Dr Tom Lewis said the group's composition was unique during the time of the White Australia policy.
"There were a number of different nationalities who would bring different skills," he said.
Z Special Unit was the subject of an SBS documentary series Australia's Secret Heroes which featured interviews with original Z members — and put descendents of the operatives through the unit's arduous training.
Sworn to secrecy, Z veterans were not allowed to tell anyone of their experiences until 1980.
"At the end of the war when we were discharged out of Z Special Unit the operatives had to sign a secrets act," Mr Tredrea said.
"It was so they would not discuss what they did for 30 years.
"It was not until 1980 at a national reunion in Melbourne that we knew what the next guy did."