Suggestions for other poisons flowed thick and fast. Probably every kind of poison growing in backyards in Sydney was suggested. Dry ice in the boot of Bogle's car was suggested. There was even a suggestion that some kind of nerve gas, contained in a pea-sized capsule, was crushed under one of the pedals of the car. Examination of the car found no trace of any capsule.
Also touted as a possible was the poison of the Conus geographus, a shellfish found on the Great Barrier Reef. It was said that Bogle's research may have been into this venom, or something similar. As it happened, the bodies were tested for the poison. Once again, no trace was found.
Other speculation: