This extract was originally published in the Sydney Morning Herald - a German crewman describes Australia's biggest World War II disaster.

Children are renowned for asking difficult questions. But Heinz Messerschmidt was unprepared for the question his son was about to ask as he looked up from a photograph of the officers and crew of Austrlia's World War II cruiser HMAS Sydney: "And all these men were killed by you?" he asked.

"Yes," said Mr. Messerschmidt, "All of them."

As a 26-year-old lieutenant commander on the German raider Kormoran, Mr. Messerschmidt witnessed the murderous barrage that san the Sydney and led to a mystery that remains today: Why did none of the 645 crew members of the Sydney survive to tell their tale?

Mr. Messerschmidt dismisses conspiracy theories of Japanese submarines being involved as "ungrounded speculation and a huge defamation" for the officers and crew of the Kormoran.

He explains the mystery with a closer examination of the two main figures involved: Captain Detmers, of the Kormoran, and Captain Burnett, of the Sydney.

Mr. Messerschmidt is now 83 and lives in a small, tidy apartment near Kiel in northern Germany.  He spent five years in a prisoner-of-war camp in Australia and had many opportunities to rake over the battle with Captain Detmers.

A widowerer with neatly combed white hair and a perfectly ironed white shirt, he adjusts his Kiel Yacht Club tie and says:

"Captain Detmers was a very strict man who placed great emphasis on dress and abstinence from alcohol.

"A month before our engagement with the Sydney, Captain Detmers celebrated his birthday.  We were allowed to drink  Whisky, and one of the crew members got a bit drunk and let his tongue run loose.

"Detmers cut him short straight away, saying that he would like to make something very clear to the assembled gentlemen, and that was that our moment of truth would come when we had a visit from the "Grey Steamship Company', as in the British Navy, and by inference their Australian allies, were referred to.

"Then he said no more whisky and that was the end of the evening."

Mr. Messerschmidt shuffles his folders and memorabilia relating to the Sydney and looks over his glasses. "And Captain Detmers was exactly right, and not for the first time.  He sensed that a visit from the Grey Steamship Company was on the way.

"As the Sydney approached, he sensed that they wanted to continue on their southerly course and that they were not prepared for any irregularities.

"Campain Detmers said the Sydney would come by, say many thanks, wish u bon voyage and see you later.

"He ordered everyone below and said the Sydney would notice nothing and that we would get away with it, referring to the disguise of a Dutch merchant vessel the Germans were using.

"He was the right man for an undertaking of our nature, a Himmelsfahrtkommando as our ships were know (suicide mission}; he could always sense that little bit more.

"Basically, all the survivors from the Kormoran, all of us, must thank Captain Detmers for his finger-tip touch.  Without him everything could have run differently from the start."

Captain Detmers said right from the first contact with the Sydney that the Australians weren't suspicious.

"The Sydney failed to make a thorough investigation of who we were, and came far too close.

"You have to picture it. It was late November and the Sydney was in the Western Australian waters; the crew had warred hard in the Mediterranean and had bee successful in conjunction with the British Navy.

"What should a merchant raider be doing in these waters, so close to the Australian coast?

"W had disguised ourselves as the Dutch merchant ship Straat Malakka, and carried a Dutch flag.

"A raider simply could not be in these waters

"And they must have thought 'But we have the assignment to a least clarify who it is'. The Sydney asked what type of cargo we had, where we were traveling to --- but we didn't have the secret signal and letters [in reply].

"Basically it was this signal that was the death sentence for the Sydney and the cause of this terrible chapter of history for Australia."

Mr. Messerschmidt wanders back in time. "As the Sydney approached we could see that they had prepared to send up their spotter plane, which would have given us away because we had a deck cargo of mines.

"But then the plane was suddenly put back into its normal position .  That was the moment when Captain Detmers said 'Ah yes, it's tea-time on board --- they'll probably just as us where we are going and what cargo and then let us go on.

"Then Captain Burnett of the Sydney made the following mistakes: he came far too close and, worse still, instead of putting himself directly behind us, he put himself directly opposite.

"If he has sat behind us he could have used both forward turrets on us an we could not have brought all our weapons to bear on him.  He was only 900 meters away.  You could see the ship's cook with his hat on at that distance.

"W saw that no-one ran around on deck and that they were not alarmed.

"Detmers said 'Now comes the good journey etc', but instead come the order to hoist your secret signal. Detmers immediately ordered the camouflage to be dropped and the German flag to be hoisted.

"Then, with anti-aircraft guns, we held the bridge under continual fire to put all the officers out of action.

"At the same time we fired torpedoes and our six-inch guns.

"The Sydney was not ready for battle.  The four turrets were not trained on us and the torpedo tubes were not manned. As we opened fire, the crew started running for the torpedo tubes, but we held the torpedo tubes under contant fire with our guns so they couldn't get there.

"This is the murderous nature of the attack, when a totally unprepared cruiser lies in such close range to what it believes is a Dutch merchant ship - which within a minute can transform itself into a warship.

"The six-inch shells were armed in the base and not the nose, so they went over the short distance and pierced the armour and exploded inside the ship.

"It was half an hour of continual fire. It's a surprise no one survived.

"The few that did survive the initial onslaught were the firing officer and crew of the rear X turret, who fired three times and hit us in the magazine, once amid ships and the third time through the funnel, while was used to pre-heat the oil before it was pumped back down into the motors.

"You can picture what happened as the hot burning oil flowed back down into the engine room.  Only one man survived. The we had not power and could not put the fires out.

"It was then we realised it was all over for us.  We would have to abandon ship and would be picked up as prisoners."

Heinz Messerschmidt flicks through carefully arranged photos and reveals the stranger side of his encounter with the Sydney.

"In the mid 1930's I was a midshipman on a training cruise and we were docked in Cadiz in Spain at the same time as the Sydney.  The photo here is the Sydney. It was docked opposite and both crews made tours of the respective ships. I went on board the Sydney  and met come of the crew and took some photos of them."

He shuffles his memorabilia and extract another small photo with a large Australian face beaming across is and the words HMAS SYDNEY clearly emblazoned on his cap.

"I don't know who this man is, nor if he was on the Sydney at the time of the encounter with the Kormaran, but non of us would have dreamt that we were to meet again, and under such different circumstances."

Mr Messerschmidt pauses. His memories of the Australia are full of warmth towards the Australians who treated him so well, not only as a prisoner-of-war but also as a tourist and guest of the RSI.

"You all make so much effort to find another answer as to the fate of the Sydney," he says wistfully.

"This is everything I have collected over the years on the Sydney and Kermoran.  I gave back my Iron Cross to one of the prison guards in Australia just before we were shipped back to Germany on the Steamer "Orontes."

An then there was a final twist in the tale; the ship lying next to the Orontes in Port Melbourne was the real Straat Malakka.