Nauru's Supreme Court is expected to rule on the eligibility of the health minister to serve as an MP next week.
Last week, Dr Kieran Keke was suspended from parliament after the opposition claimed his dual citizenship made him ineligible.
The speaker of parliament, Russell Kun, has referred the matter to the Supreme Court.
Mr Kun says Dr Keke should not be allowed to carry on as minister until the matter is resolved.
"For me it's a constitutional issue so he should be relieved from all his duties also, that's my opinion though. Now I believe he is still running around doing his day to day business as minister."
Russell Kun says Dr Keke had allegedly used his Australian passport when conducting government business.