The Refugee Council of Australia says the rejection of Papuan David Wainggai claims for asylum is proving problematic.
Wainggai is one of the 43 asylum seekers who arrived in Australia in January, saying they were fleeing persecution in Indonesia.
While 42 of the group were granted protection visas, Mr Wainggai's application was rejected on the grounds that his mother has Japanese citizenship and he may be able to live in Japan.
Through his legal representative David Manne, Mr Wainggai, who remains in detention on Christmas island, is appealing the decision to the Refugee Review Tribunal.
The Refugee Council's President, John Gibson says there's no guarantee Japan recognises Mr Wainggai or his rights as he seeks asylum.
"His mother was a Japanese national and therefore he had those entitlements. Now from what I've read that David has said publicly that's problematic: he's never had a Japanese passport and the argument that his representatives will be making to the Refugee Review Tribunal is that that section would not apply."
The Refugee Council of Australia president John Gibson