Five Chinese men jailed for importing the drug "P" have appealed against their convictions and sentences.
Two of the five were jailed for life in December last year and the others received jail terms of between 15 years and 19 years.
The men imported 96 kilograms of methamphetamine, hidden in plastic blocks in the bottom of paint cans, and 154kg of pseudoephedrine hidden in bags of cement plaster.
The drugs were valued at $135 million.
Lawyers for the men raised questions at the Court of Appeal on Thursday about the evidence of transactions and shipments produced by the Crown during the trial.
The Crown says the cases against the men were well founded.