BARCELONA, Jan 19, 2023 (BSS/AFP) - A Spanish great-grandmother who was born in the United States has likely become the world's oldest living person at 115, a Guinness World Records consultant said Wednesday.

Maria Branyas Morera is believed to have assumed the title following the death on Tuesday of French nun Lucile Randon aged 118, senior consultant for gerontology Robert D. Young said.

Guinness World Records must still make the official decision after carrying out document checks and interviewing Branyas Morera's family, added Young, who is also the director of the Gerontology Research Group's supercentenarian research database.

"We know what is likely but it's not confirmed at this time," he wrote in an email sent to AFP.

Branyas Morera, who has lived through the 1918 flu, two world wars and Spain's civil war, was not available for interviews.

The Santa Maria del Tura nursing home in the town of Olot in northeastern Spain where Branyas Morera has lived for the past two decades said it would hold a "small celebration" behind closed doors in the coming days to mark "this very special event".

"She is in good health and remains surprised and grateful for the interest that has been generated," it added in a statement.

Branyas Morera's youngest daughter, 78-year-old Rosa Moret, attributed her mother's longevity to "genetics".

"She has never gone to the hospital, she has never broken any bones, she is fine, she has no pain," Moret told regional Catalan television on Wednesday.

Branyas Morera was born in San Francisco on March 4, 1907 shortly after her family moved to the United States from Mexico.

Her family moved to New Orleans in 1910 where her father founded a magazine in Spanish called "Mercurio".

The entire family decided to return to their native Spain in 1915 as World War I was under way.

In 1931 -- five years before the start of Spain's 1936-39 civil war -- she married a doctor.

The couple lived together for four decades until her husband died aged 72.

She has had three children, including one who has already died, 11 grandchildren and 11 great-grandchildren.

"I haven't done anything extraordinary, the only thing I did was live," she said during a 2019 interview with Barcelona-based daily newspaper La Vanguardia.