The Tautua Samoa party leader, Vaai Papu Vaelupe, has lost his parliamentary seat after the Electoral court found him guilt of bribery and treating.
The election petition was brought against the Opposition leader by an unsuccessful candidate of the ruling HRPP after last month's general election.
The court has dismissed a counter petition by the Opposition leader against the petitioner, Tufuga Gafoaleata Faitua, because the respondent could not prove his allege bribery and treating allegations.
It is not clear if the petitioner will be automatically appointed as new the MP for Vaisigano number one or if a by-election will be called, but the court will inform the parliamentary speaker about the outcome of the case.
Meanwhile the Tautua Samoa party caucus is expected to meet sometime this week to select a new leader.
A first time opposition MP, Afualo Dr Woods Salele, says it will be easy to find a new leader because the remaining 12 opposition MPs are capable of leading the party.