SYDNEY (Reuters) - A bullet found inside a skull buried on a remote Indian Ocean island has added further intrigue to Australia's greatest naval tragedy, the mysterious World War Two sinking of a warship with the loss of all 645 hands. The light cruiser HMAS Sydney II sank somewhere off Western Australia's northwest in November 1941 after it came under fire from a German raider, thought to be the Kormoran disguised as a Dutch merchant ship. The Sydney has never been found after it sailed ablaze over the horizon at the end of a fierce 30-minute battle. Australian defense officials said a navy team had this month exhumed the remains of an unknown sailor buried in an unmarked grave on Christmas Island, remains long thought to be those of a Sydney crewman. Islanders have said the unmarked grave contained the remains of a man dressed in a blue boilersuit which washed up in a navy liferaft in February 1942. A complete skeleton of what appeared to be a relatively young Caucasian male has been recovered along with other items and been sent for analysis. "The most interesting find to date has been what appears to be a bullet wound in the skull and a small caliber round that is currently undergoing detailed analysis," team leader Captain Jim Parsons said in a statement. "This round appears to be from a low-velocity weapon, possibly a handgun," he said. The navy's official version of the battle (www.navy.gov.au), based on incomplete accounts from Kormoran survivors, says the disguised German ship lured the much more heavily armed Sydney in close and then opened fire with torpedoes and six-inch guns. It says the Sydney was "crippled and on fire from bridge to the after funnel" as it steamed slowly southwards until it disappeared from view and "all that was seen was a distant glare and occasional flickering."