An Indonesian prosecutor has demanded that four Australians each be jailed for three years for violating immigration laws in Papua.

Queenslanders Vera Scott-Bloxam, 54, Hubert Hufer, 57, Karen Burke, 51, and Keith Ronald Morimter, 60, are facing trial in Merauke District Court.

They are accused of entering Indonesia illegally, after they travelled to Papua by a small plane from Horn Island, off the tip of Queensland's Cape York on September 12.