Jakarta - Five Australians arrested last year after landing a small plane in Indonesia's eastern-most province of Papua should be able to go home soon after a court upheld their acquittal, their lawyer said Thursday.

In January, a court in Merauke district sentenced the Australians to between two and three years in prison after convicting them of landing a small plane illegally and entering Indonesia without visas in September.

Papua's appeals court overturned the conviction but prosecutors appealed against the ruling to the Supreme Court, which on Wednesday ruled in favour of the Australians, their lawyer Efrem Fangoihoy said.

Fangoihoy said his clients could leave Indonesia next week after they receive an official copy of the verdict.

The Australians said they had flown to Papua to explore tourism business opportunities and assumed they could get visas on arrival.

Papua is home to a low-level separatist insurgency and visa-on-arrival regulations are only applicable at major ports. (dpa)