On March 20, 1995, members of the Japanese doomsday cult Aum Shinrikyo released sarin gas into Tokyo's subway system during the morning rush hour, killing 13 people and injuring thousands.
When news of the attack emerged, the Australian Federal Police discovered an unexpected connection: in 1993, the cult had purchased and made multiple visits to Banjawarn, a remote sheep station in the West Australian desert. A police raid of the station, which the sect sold in October 1994, revealed a laboratory hidden in an abandoned house, equipped with computers, beakers, tubing, Bunsen burners, mixing bowls, a rock-crushing machine, and generators. Chemicals and 29 sheep carcasses completed the picture: Aum Shinrikyo had been conducting nerve-agent experiments on the animals in preparation for international attacks.
Police concluded that sect once intended to establish a permanent haven in Australia, but found no evidence of its members living in Australia. Banjawarn has reverted to its pastoral origins, operating as a cattle farm with a four-bedroom cottage, garden, and orchard. However a mystery remains.
On May 28th 1993 a mysterious seismic disturbance was detected emanating from the area. The disturbance was "170 times more powerful than the largest explosion known in Australia up to that time." Long distanace truckers report having seen a fireball and heard a loud low frequency sound. This event occurred during the time that Aum Shinrikyo is known to have been conducting sarin experiments on sheep at the remote station.
It is also now known that the Aum Shinrikyo cultists had been interested in acquiring or creating nuclear weapons, and recruited Russian nuclear weapons engineers to help them. Some have speculated that Aum Shinrikyo may have set off a homemade explosive device in the remote area, though an investigation found no evidence of this, nor any other clear explanation for the seismic event and reported fireball.
In his book A Sunburned Country Bill Bryson notes that Australia is "so vast and empty that a band of amateur enthusiasts could conceivably set off the world's first non-governmental atomic bomb on its mainland and almost four years would pass before anyone noticed".