In a landmark Hong Kong court ruling in September, six westerners – including two Australians – were set free despite having been caught with commercial quantities of crystal methamphetamine while attempting to board flights to Australia. Prosecutors offered no evidence, effectively dropping their charges, after determining they were duped by sophisticated international crime syndicates into becoming unwitting drug mules. Anthony Bannister appearing in Guangzhou People's Intermediate Court in 2014. Of the 10 foreigners arrested in similar circumstances, a further two have since been released. The remaining two, Australians James Clifford and Kent Walsh, are hopeful of being exonerated as their cases progress in the coming months. Back in Guangzhou, however, as many as a dozen Australians remain stranded on charges which could attract the death penalty despite – at least in those cases where details have come to light – credible evidence they have been caught up in similarly callous scams which have rendered them collateral damage in the ruthless ice trade between southern China and Australia. Along with other Australians – including Peter Gardner, Ibrahim Jalloh and Bengali Sherrif – whose pleas of innocence have so far fallen on deaf ears, Bannister's chances of an overturned verdict appear slim. Mainland China's opaque and party-controlled judiciary sees conviction rates of close to 100 per cent once formal charges are laid. Though directly across the border from Guangzhou, Hong Kong has retained its independent judiciary since its return from British rule in 1997.

Bannister's Chinese lawyer, Zou Jianhong, hopes the introduction of new documentary evidence will help prove to judges that his client was scammed. Bannister has long argued he had been duped by online scammers who had convinced him into believing he could obtain a lucrative divorce settlement, having recently split from his ex-wife. Australian Peter Gardner arriving at Guangzhou People's Intermediate Court in May 2015. Credit:Sanghee Liu After being told to travel to Guangzhou in March 2014 to sign a series of documents relating to the purported 'settlement', he was asked just before his return flight to bring back a suitcase with him as a favour. He said he never looked in the suitcase, which contained women's handbags - filled with the drugs. Though Bannister's claims seemed convoluted and, in the words of prosecutors, "illogical", solicitor Christopher Morley – who represented five of the 10 foreigners arrested in Hong Kong – said they fit closely with the pattern his clients experienced at the hands of sophisticated online scam artists who preyed on vulnerable and easily susceptible targets. Ibrahim Jalloh at Guangzhou People's Intermediate Court in July 2015. Credit:Sanghee Liu

"To you and I, I suppose they appear to be easily duped, you might consider them to be daft," he said. "But when you see the elaborate way they've been set up, sometimes over a matter of years, you can see how their confidence in people who are tricking them and you can see how it builds up." Barrister Michael Arthur, who has acted for all 10 of those arrested in Hong Kong, agreed. "I wouldn't be in the slightest bit surprised if the Australians [in mainland China] were tricked in the exact same way as [my clients] in Hong Kong," the New Zealand-born lawyer said. "They are very similar cases," he said of Bannister's case. Joerg Ulitzka was detained in Hong Kong on suspicion of drug trafficking before being freed. Guangdong is a major global manufacturing hub for synthetic drugs, favoured by international trafficking syndicates for its transport links and lax regulation of precursor chemicals. The report from the National Ice Taskforce, commissioned by the Abbott government, says 70 per cent of ice shipments intercepted in Australia originate from China. German-born Australian Joerg Ulitzka was exonerated in November last year after Hong Kong prosecutors accepted that he had no knowledge of the ice in his luggage. Instead, he had fallen for a "black money" scam and believed he was carrying a large sum of cash that could only be "washed" with a specific chemical.

Brendan Toner, an electrician from Northern Ireland who was also freed, thought he was carrying a drum of electrical cables from the Canton Fair. He crossed into Hong Kong with the cables from Guangdong, before being stopped at customs while attempting to board his onward flight to Australia. James Clifford, who remains in Hong Kong on bail, says he travelled to the city in the belief he was signing documents that would grant him a $US2.3 million inheritance. Of those languishing in Guangzhou detention, Sydney man Peter Gardner says he thought he was carrying performance-enhancing peptides in his bag. Ibrahim Jalloh, who is intellectually disabled, says he went to Guangzhou in the belief he was bringing back some "important documents" in return for a $15,000 fee. And 64-year-old Gold Coast pensioner John Warwick died in a prison hospital in Guangzhou in 2014, having been arrested on suspicion of concealing 1.9 kilograms of ice in a DVD player. His daughter Amanda Davis said he was lured to the city by an online lonely hearts scam.Despite the arrests, international drug syndicates appear to be continuing to use human couriers to traffic drugs from South China. Mr Morley said he was handling the cases of two more foreigners caught with ice in Hong Kong who were attempting to board flights to Australia. Do you know more? Email pwen@fairfaxmedia.com.au