An Australian opposition Greens Senator, Kerry Nettle, says if three Papuan men, being held in custody on an island in Torres Strait, claim asylum, that request must be heard in Australia.
The three men were found on Boigu Island on Saturday although the Australian government did not announce they were being held until Tuesday.
Boigu Island is a so-called excised place and the minister for immigration and multicultural affairs, Amanda Vanstone, says this means the men are classified as offshore entry people and so any application for protection will not be processed in Australia.
She also says they are not entitled to make an application under the Migration Act.
But Senator Nettle says if the three men are claiming asylum their claims should be processed in the same way as anyone who seeks asylum in Australia.
"So we believe that they should be processed in Australia under Australian law, and we are very concerned that what the government proposes to do is not in adherence with our international obligations under the Refugee Convention."