An Australian student was due to go on trial for her life today, facing a possible death sentence by firing squad for alleged drug trafficking. Schapelle Leigh Corby, 27, of the Gold Coast, Queensland, was arrested at Bali airport last October after customs officers found a plastic zip-lock bag containing 4.2 kilograms of cannabis in her bodyboard bag. Drug trafficking charges carry the death penalty in Indonesia. 'The customs officer asked the suspect to empty the contents of the bodyboard bag one by one,' prosecutor Ida Bagus Wiswantanu alleges in court documents. 'There was a big plastic bag containing dried flowers. The suspect was asked about that package and admitted it was marijuana belonging to her.' Customs officers first became suspicious after X-raying luggage taken off the Qantas flight, which flew to Bali from Brisbane via Sydney. They monitored the luggage carousel and saw a 'nervous' Corby pick up the bag containing the suspicious package. She refused to open the bag in public, so they took her to a private room, the prosecution indictment alleges. However, Corby has denied admitting the marijuana was hers. Family and friends claim she has never been involved in drugs. The Indonesian officer in charge of the investigation, anti-drugs squad director Bambang Sugiarto, said it was the largest quantity of cannabis intercepted in Bali and the first such case involving an Australian. However, he said there was a lucrative market on the resort island for high-grade marijuana. Her lawyer said it was nonsensical to believe somebody would smuggle drugs to a market where their street value was much lower. 'There is no motive to bring marijuana from Australia to Bali, and there is no crime without a motive,' said Vasudevan Rasiah, a member of the defence team. Australian Foreign Minister Alexander Downer has called the case 'very curious' as most drug trafficking arrests in Indonesia were of people trying to smuggle drugs out, not in. But Mr Rasiah has criticised the Australian government for not doing enough to help his client. 'The girl has been kept in the worst condition for the last three months ... she is being denigrated by local media,' he said.