The Australian Federal Police say an expert made the bomb that killed nearly 200 people in Bali last month. Australian investigators are part of the an international team hunting those responsible for the blast.

Australian forensic experts say a highly skilled bomb maker used chlorate to build the explosives. In September a large amount of chlorate was stolen on Indonesia's Java island and the theft is being investigated. Indonesian officials, however, think other materials were used in the bomb.

Graham Ashton from the Australian Federal Police thinks two bombs were set off by remote control. The first ripped through an Irish pub seconds before an explosion destroyed the Sari club on the opposite side of the road, in Bali's popular Kuta entertainment district. "The bomb was planted immediately prior to its detonation so somebody has planted that bomb there and a very short time later the bomb was detonated," he said.

Australian investigators say the bomb was in a van outside the Sari Club. It was, investigators say, placed to create the most possible casualties.

About 120 Australian police and intelligence officers have been working in Bali with investigators from Indonesia, the United States, Britain and Japan.

The Australian team is heading home but will continue to help the investigation by using revolutionary laser technology. It has developed a virtual map of the Sari club's interior using a three-dimensional computer image, to allow detectives to re-create the events of October 12.

At least 180 people were killed in the blasts in the Kuta beach district on Bali. Most of the casualties were foreign tourists, and least 90 Australians are among the dead and missing.

Indonesian police say they have identified one of three men wanted for questioning in the bombing. The men were spotted near the scene of the explosions and drawings of them were released to the public this week.

Australian authorities suspect the Southeast Asian group Jemaah Islamiyah in the bombing. The homes of suspected sympathizers of the hard-line Islamic organization were raided across Australia earlier this week in a nationwide sweep. The group has been linked to the al-Qaida terror network.

The raids have drawn criticism from civil libertarians, but the government says they were necessary and will continue if needed.