All were fully vaccinated and had tested negative for Covid-19 before departure.
The new cases are Samoa's largest group on one flight since the start of the pandemic.
Samoa's director-general of health Dr Take Naseri said yesterday all of the passengers who tested positive since arriving in Samoa had been put into isolation and all were asymptomatic.
Naseri said test samples would be sent to New Zealand on the first available flight to determine which variant of Covid-19 they are dealing with.