The three are the last speakers of Dusner, an ancient language spoken in a fishing village in the jungles of the Indonesian island of Papua, The Daily Telegraph reported Thursday.
Researchers from Oxford University's Faculty of Linguistics, Philology and Phonetics discovered the language only last year, the newspaper said.
Researcher Suriel Mofu set off for Indonesia in October to record and document the language.
Days after Mofu left Britain, floods ravaged the Papua province and there were fears about the survival of the Dusner speakers, two women age 60 and a man in his 70s.
"The flood in Indonesia has been a real tragedy for the inhabitants of this wonderful island and it's been a nervous few months waiting to hear whether or not our speakers survived," Mary Dalrymple, the project's leader, said, adding Mofu has since made contact with the Dusner speakers. "But this illustrates why our project is so important -- we only found out that this language existed last year, and if we don't document the language before it dies out, it will be lost forever."
Use of the language has dwindled as many locals now teach their children Malay, which they consider more useful in getting employment.
Dusner is still used in ceremonies, the researchers said.