After 65 years, submarine gives up its macabre secret

Sixty-five years after it vanished, a Japanese midget submarine that sank an Australian warship in Sydney harbour during the Second World War has yielded up its secrets.

The two-man submarine was one of three midgets that sneaked into the harbour in May 1942 to attack the American battle cruiser USS Chicago. Two were damaged and scuttled by their occupants, who shot themselves. The third fired a torpedo that missed the Chicago but blew up a converted ferry, HMAS Kuttabul, killing 19 Australian and two British ratings.

The third submarine disappeared under heavy fire, and could not be found. It became one of Australia's most enduring maritime mysteries. In November, recreational divers stumbled across it, in 54m (177ft) deep water off Sydney's northern beaches. The location of the 46-tonne submarine was kept secret while military divers examined the wreck.

This week the site was disclosed by the government, which said the bodies of the crew, Petty Officer Mamoru Ashibe and Sub-Lieutenant Katsuhisa Ban, were probably still inside. It will be left undisturbed. Divers collected a jar of sand from the seabed beside it, to present to the families of the men.

The site has been declared a protected zone, with exclusion enforced by alarms and cameras, and fines of $1m (£416,000). Australian authorities said it would be too difficult and expensive to salvage the wreck in open sea.

Mr Ashibe's brother, Itsuo, told Australian television earlier this year that he hoped the submarine would be raised. "I would like to take home an article left by my brother, or even a broken piece of the top of the sub," he said. "Then it would mean my brother came home."

The submarine was entangled in torn fishing nets, which navy divers cut away in order to map and survey it. Photographs show it sitting upright on the sea floor, largely intact.

The daring assault by the midgets shook Sydneysiders out of their apathy, and sparked fears of a Japanese invasion. Until then, despite the fall of Singapore and the bombing of Darwin in the north, locals had felt untouched by the war.

The subs, launched from a mother submarine 35 miles east of Sydney Heads, were on a mission to divert Allied naval power from the decisive battle fought near Midway in the Pacific, a week later in June 1942.