Vanuatu's Seventh Day Adventist Mission says it is disappointed at the quiet sale of the church's former prime real estate, Turtle Island.
The church general secretary, Pastor Damien Rice, says he only found out by looking at properties for sale at a real estate agent on Santo.
The island has been sold to an investor for close to 400,000 US dollars.
The SDA Mission handed over the island to the government in 1983 because the government said it wanted to turn it into a conservation area.
He says it is the ni-Vanuatu people who lose out.
"It's a place that the people of those islands have recognised as somewhere where they can go and visit, spend the day, enjoy time there with family and community. And there are becoming fewer places that the public can go access and enjoy. Some of these kinds of things can have a detrimental and negative impact on the quality of life for people, and two, for a nation whose people are so closely tied to the sea this really isolates them from a source of their identity."
Vanuatu's Seventh Day Adventist Mission pastor, Damien Rice.