A young Australian man has been sentenced to death and another is awaiting trial after being caught by Chinese authorities trying to smuggle methamphetamine from China to Australia.

Queensland man Ibrahim Jalloh and another Australian citizen, Bengali Sherrif, were arrested by the Chinese authorities at Guangzhou airport in June last year, but until now their plight has remained secret.

The ABC understands Sherrif was sentenced to death for attempting to traffic the drug, which is used to make ice, but this will be commuted to life in prison if his behaviour in prison is good for two years. Jalloh has apparently not been tried yet.

The two men are among a number of Australians arrested and held in China over drug-related crimes, but precise details about the prisoners are difficult to come by.

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News of the arrests emerged in a Melbourne court last week during a committal hearing for three men charged over an alleged conspiracy to import drugs from China.

Sam Komba, 20, and Foday Kamara, 29, both of Queensland, were ordered to stand trial on one charge of conspiring to import a controlled substance.

Melbourne man Wedi Bembo will be tried for the same offence, and also over an alleged heroin importation in 2013.

At the hearing in Melbourne Magistrates Court, an Australian Federal Police officer gave evidence that the AFP were tipped off by Customs in December 2013 that two kilograms of heroin sent from India had been intercepted.

Federal Agent Sarah Brener said the AFP then began intercepting telephone calls, which eventually led them to a man described as "Sammy Africa", who they alleged was actually Bembo.

Suitcase wrapped in plastic delivered to hotel: court

In May, according to Ms Brener, the police listening to the phone calls became aware of a planned importation of drugs from China. From the intercepted conversations, they initially believed the syndicate was sending six couriers to China, but it became clear by the end of May there were only two.

Ms Brener said this information was passed to an Australian Federal Police liaison officer in Guangzhou. However, the ABC understands the information was not passed on to the Chinese authorities.

Sometime between June 6 and June 8, Jalloh and Sherrif were arrested at Guangzhou airport, allegedly with a substantial quantity of methamphetamine.

Jalloh's brother, Chiwto, gave evidence that he and Ibrahim had arrived in Australia from Sierra Leone with their mother and three sisters about eight years ago.

Chiwto said he moved from Sydney to Brisbane, where he met Sam Komba through casual football matches and parties at nightclubs. He then moved to Adelaide.

In April last year, according to evidence given by Chiwto, Sam Komba phoned him and asked if he wanted to accompany him on a trip to South Africa to "pick up some passports". According to Chiwto, Komba said his trip would be paid for.

Chiwto went with Komba to South Africa, where the two men stayed at a Johannesburg hotel for more than three weeks. Chiwto told the court he was not suspicious about the purpose of the trip, and would not have gone if he believed it had anything to do with drugs.

He said at some point during the trip, a large suitcase wrapped in clear plastic was delivered to Komba at the hotel.

Chiwto eventually flew back to Brisbane, carrying nothing more than the small suitcase and a carry bag he took with him.

He told the court that sometime after his return, he met with Komba, Kamara and another man. He was given some money "in appreciation" of his trip to South Africa, but warned to keep his mouth shut.

Mother received phone call alerting her to Ibrahim's arrest

He said he was also asked if he wanted to go on another trip, this time to China, but declined.

Chiwto said soon after this, he was contacted by his brother, who told him he was in China at the behest of Sam Komba — who knew Ibrahim as well — to pick up some passports.

He said he was not particularly concerned by this, but then his mother received a phone call from the authorities to say Ibrahim had been arrested.

Chiwto told the court he then phoned Komba, saying to him: "Sam, my brother has been caught, if you don't do something it will not be good."

Chiwto said Komba vociferously denied he knew anything about the drugs, and told Chiwto he would make enquiries and get back to him, but that was last he heard from him.

Federal Agent Brener also gave evidence that telephone intercepts showed two other men, named "Jacques" and "Mike", were aware of the couriers' movements, and that Jacques is believed to have been with them in China at some stage.

A trial date has been set for October.