The trial of Dominic Jude Bird, 32, of Perth began Monday in the Kuala Lumpur High Court, The Australian reported.
Bird is accused of drug trafficking and drug consumption, which carries a mandatory death penalty if he is convicted. He has pleaded not guilty.
Police alleged Bird offered to sell 167 grams of methamphetamine to undercover officers in March, shortly before his arrest.
The prosecution has so far called police witnesses, as well as a chemist who was responsible for testing the drugs allegedly seized from Bird, the Australian Broadcasting Corp. reported.
Bird's attorney, Muhammad Shafee Abdullah, questioned the chemist's forensic analysis, alleging an insufficient amount of the drugs were tested.
"She didn't test enough," Shafee said. "What we have established actually is very critical."
Bird's trial is expected to last through Friday.