DNA evidence has finally confirmed that a Royal Australian Navy sailor whose body was found in a life raft near Christmas Island in February 1942 came from the light cruiser HMAS Sydney (II), which vanished with all its 645 crew after a battle with a disguised German raider off Western Australia.

The Sydney was the pride of the Australian fleet and regarded as invincible after defeating two Italian warships in the Mediterranean. It was on a routine voyage home to Fremantle after escorting a troop ship to Singapore when it came upon the German auxiliary cruiser HSK Kormoran, a merchant ship heavily armed with concealed guns and carrying a cargo of mines to be laid around the Australian coast.

The battle which destroyed both ships raged 120 nautical miles off Steep Point on the evening of 19 November 1941. More than 300 Germans survived and spent the rest of the war in Australian prisoner-of-war camps.

The decomposing body of the sailor now identified as Able Seaman Thomas Welsby Clark was found on the raft, known as a Carley Float, 11 weeks after the battle. He was buried in an unmarked grave on Christmas Island just before Japanese forces occupied the island. The remains of the rangy 21-year-old from Brisbane were exhumed in 2006, and then began the protracted search for his identity. His niece, Leigh Lehane, was born in July 1941, a month before Clark joined the Sydney, and he’s understood to have visited her on a final trip to Brisbane. ‘He came and held me as a little baby,’ Lehane told researchers. ‘That’s a very pleasurable thought because I don’t think anyone is alive now who knew Tom sort of eye to eye.’

That mystery has been solved, but the question that’s unlikely to ever be answered adequately is why the Sydney closed to within 1,000 metres of the Kormoran. An inquiry later noted that was virtually point-blank range for naval guns.

The lack of Australian survivors triggered years of dark conjecture about the fate of the Sydney and its crew, including claims that the warship was destroyed by a Japanese submarine and that Australians were murdered in their lifeboats. Over decades, these claims have all been debunked, but the absence of an explanation for why the Sydney was lost with all hands remained deeply disturbing for families and friends who were without a focus for their remembrance.

The wrecks were found on the seabed in 2008 and former judge Terence Cole was commissioned to carry out a major inquiry into the Sydney’s loss, drawing on what could be gleaned from the location and condition of the sunken vessels.

Cole largely accepted the German accounts of the battle and rejected the multiple claims of foul play. He blamed the cruiser’s captain, Joseph Burnett, for its loss, but he noted that Burnett was considered an exceptional officer facing huge pressures and declined to make a finding that he was negligent.

The graphic testimony Cole heard from German survivors and the extraordinary pictures of the two wrecked ships on the ocean floor revealed the appalling last moments of the Sydney and its crew.

The Kormoran’s survivors described how the Sydney was spotted at about 4 pm and some of the crew thought it was a sailing vessel because of its high masts. They quickly realised it was a cruiser and were ordered to battle stations.

Elderly but with clear memories of the battle, the Germans described their fear as the Sydney approached looking ‘powerful and beautiful’ in the early evening light. Former officer Heinz Messerschmidt said the Kormoran’s captain, Theodore Detmers, recognised that the raider would one day meet a ship from what he called ‘the grey funnel line’. Detmers and his officers trained the gun crews constantly so that it would take just six seconds for them to de-camouflage and open fire.

Messerschmidt said the crew had ‘scrounged’ from the German army two 37-millimetre, quick-firing anti-aircraft guns that were placed on either side of the raider’s bridge. These became a key to the rapid German victory.

The Germans were under instructions to stay clear of allied warships where possible but, if battle could not be avoided, ‘every attempt to destroy the enemy by means of camouflage, by unexpected and ruthless use of all weapons should be made’.

The Kormoran’s gunners trained twice a week to load and fire their weapons quickly and accurately. Detmers told each gunner where to aim if the raider ever met a warship. The hours invested each Thursday and Friday proved devastatingly effective when the Kormoran finally engaged the Sydney.

For more than an hour, the Sydney tried to communicate with the Kormoran using flag signals and a signalling lamp. The Germans sent vague and confusing replies. Detmers turned his ship into the sun to make it even harder for the Australians to read his signals.

The Germans described how, soon after 5 pm, the cruiser closed in with its guns and torpedo tubes pointed at the raider. ‘The situation was becoming very tense,’ Messerschmidt said. ‘I knew that one shot from the cruiser into the mine deck would kill us all.’

The Germans signalled that they were the Dutch freighter Straat Malakka. Burnett then asked them to send their secret recognition sign. ‘We were terrified,’ Messerschmidt said.

Detmers told his crew he didn’t know the sign and they’d have to fight.

By then, said Cole, Burnett must have known that the ship he was confronting was no innocent merchantman. But it was too late and moments later he was dead. Detmers ordered the Dutch flag to be struck and the German battle ensign hoisted. Cole said that took between 8 and 15 seconds. The battle flag would have been clearly visible as it rose. ‘The German war ensign was flown before the first shot was fired,’ Cole concluded.

On the Kormoran, Detmers said: ‘It’s now or never!’ and then gave the order to lower the large, hinged flaps hiding his guns and open fire.

Cole said it appeared that the Kormoran fired first but the Sydney fired back almost simultaneously.

The 37-millimetre gun crews had been trained to concentrate on the bridge of an enemy vessel, Messerschmidt said. ‘At short range such guns are horribly effective. I could see shells with a covering arc of fire hitting and wiping out the many men on the bridge.’

As Detmers had so carefully planned, salvos from the Kormoran’s big guns hit the Sydney’s bridge, the gunnery control tower, the engine room, and the Sydney’s Walrus aircraft, which blew up and started a huge fire.

Cole said it was likely that Burnett and most of his officers were killed as the battle began and about 70% of the crew probably died within minutes.

Messerschmidt said it was ‘horrible to see it unfold’ as the unprepared (according to German accounts) Australian crew made desperate attempts to fight back. ‘I saw men running to Sydney’s torpedo tubes being shot down.’

Then the Kormoran fired a torpedo that hit the Sydney about 20 metres back from the bow. The Sydney scored three or four hits on the Kormoran, which stopped the raider. The cruiser turned and fired two torpedoes, which missed the Kormoran.

The Sydney’s guns were each taken out with precise and deadly shots from the highly trained German gunners. Those holes are clearly visible still in photos from the sea floor. Soon, only one of the cruiser’s four twin turrets was firing. Then it was hit and its crew killed, and the Sydney eventually turned away and headed slowly for the horizon, heavily ablaze.

Messerschmidt said the ship appeared as a fire shower—‘like the sun setting’. It seems the cruiser exploded and sank at around midnight.

Cole concluded that during the short, brutal battle the Sydney was hit at least 87 times by heavy shells from the German raider and with hundreds of lighter explosive rounds.

The raider, too, was fatally damaged, and Messerschmidt said he set timed explosive charges that blew it up after its survivors took to their lifeboats. He said he never saw any Australian survivors in the water. ‘Both us and the Australian men on Sydney were all caught up in a cruel war,’ he said. ‘We fought hard and with decency within the rules of war.’

Cole said it was likely that most of the Sydney’s crew were killed in the fighting and those who had survived the firing would have gone down with the ship when it sank some hours after the battle. Hence, the absence of survivors.

‘Those remaining were likely to have been in the aft section of the ship, seeking to control fires, attend to the wounded, and perhaps engaged in damage control,’ Cole said. ‘Most were probably suffering from severe injuries, burns, and smoke and toxic gas inhalation.’ They were in a ship that was rolling severely. Means of escape were limited by internal damage.

The ship sank suddenly, Cole said, and the prospect of crew members surviving was remote.

Somehow, Able Seaman Clark ended up in the life raft with a severe head wound. He may have fallen into the raft or been placed there by shipmates. When the raft was found, it contained what has variously been described as a single shoe or a pair of boots that would not have fitted the sailor, raising the possibility that at least one other man survived for a time.

After Clark’s body was exhumed in 2006, an Australian officer said its skull had what appeared to be a small-calibre pistol bullet inside it. That was incorrect. It turned out to be shrapnel matching the steel used in German naval shells in World War II.

Cole said Burnett had seen intelligence reports that a disguised German vessel might be in the area, and he had told his crew in October that ‘there is an enemy raider out there’. That made almost inexplicable Burnett’s decision to place his ship in a position of great vulnerability, he said.

Cole also said Burnett had been sent lists of all merchant ships around the coast and he should have realised quickly that the Kormoran’s claim to be Dutch was false.

But historian Tom Frame, author of HMAS Sydney: loss and controversy, thinks the verdict against Burnett is mistaken. Frame believes that Burnett was somehow convinced that he’d come across a lightly armed German supply ship that was planning to meet the Kormoran and not the heavily armed raider itself.

He thinks Burnett was about to send a boarding party to capture the German vessel, while hoping to rescue any allied merchant seamen who might have been prisoners aboard it. Then he could lie in wait for the Kormoran and destroy it. Earlier in the war the Kormoran did have captured Allied sailors on board, making Burnett’s caution entirely justified.

The only reason for coming near to a ship is that you intend to board it and you do that because you think it’s safe or pruden, Frame says. Burnett was a competent officer who wasn’t foolhardy. ‘What made him think it was safe, we will never know.’

The raider was very effectively disguised, and when he became suspicious Burnett’s only options were to board it or to stand off 12 kilometres away and use the greater range of the Sydney’s guns to sink it. But if the German vessel carried prisoners, they would have been killed as well.

Burnett was in a very difficult situation and had to take some risks, Frame says.

He knew there was a raider in the area, and where there was a raider there would likely be a supply ship. There was a gamble in the action he took. He was up against a very fine raider captain and he came off second best.

Frame doesn’t believe the Kormoran surrendered to the Sydney, but it probably gave the Australians the impression it wouldn’t resist boarding. ‘I think Burnett thought he’d caught Kormoran’s supply ship and he could wait in the area and dispose of Kormoran as well,’ Frame says.

Burnett closed in and lost his tactical advantage. ‘He was certainly not incompetent and he was not reckless.’