A Maltese-Australian is among four Australian men who will be tried in Italy over drug smuggling.

Their trial will be held in absentia because Australia has refused the Italian government's requests for extradition.

An Australian newspaper reported that Michael Calleja, 51, Nicola Ciconte, 54, Vincenzo Medici, 45, and Carmelo Loprete, 41, will be tried next month in Vibo Valentia, Calabria. Mr Calleja, who was born in Malta, is from Kew.

The Age reported that the four men allegedly conspired with the Calabrian mafia to ship up to 500 kilogrammes of cocaine with an estimated street value of $50 million from South America to Melbourne through Italy between 2002 and 2004.

The alleged plot was uncovered by the Italian police in an operation code-named Decollo after an international drug network was infiltrated.

Three of the men, including Mr Calleja, allegedly made several trips to Italy to work out the details of their shipments.

Mr Calleja is suspected of having inspected the drugs and later recorded telling Mr Ciconte the "furniture" was beautiful.