Swiss researchers have vindicated the claim of a deceased French woman, Jeanne Calment, to living the longest life of any human being, by using mathematical modelling and historical evidence.

Madame Calment died in 1997 at the age of 122 years and 165 days, and was believed to hold the record for the oldest person ever.

However, in 2018 a theory was mooted by University of Moscow gerontologist, Valery Novoselov and lab assistant Nikolay Zak, who argued that it was not Jeanne Calment who died in 1997, but her daughter Yvonne Billot.

Records showed the daughter dying in 1934 at the age of 36, but the Russian researchers argued that Mme Calment was actually the person who died and that her daughter committed identity theft, possibly to avoid paying inheritance tax.