Ageing specialists Jean-Marie Robine and Michel Allard, who declared Calment the longest-lived person in the 1990s, said their review of old and new data confirmed she “remains the oldest human whose age is well-documented”.
“Recently the claim that families Calment and Billot (her in-laws) organised a conspiracy concerning tax fraud based on identity fraud between mother and daughter gained international media attention,” Robine, Allard and two other researchers wrote in The Journals of Gerontology.
“Here, we reference the original components of the validation as well as additional documentation to address various claims of the conspiracy theory and provide evidence for why these claims are based on inaccurate facts,” they wrote.
Calment, who used to joke that God must have forgotten her, died in southern France in 1997, setting a longevity record that has been questioned.
Last December, Russian researchers Valery Novoselov and Nikolay Zak claimed in a report that Calment had actually died in 1934 and that her daughter Yvonne stole her identity to avoid paying inheritance tax.
According to their research, the woman who died in 1997 was Yvonne, not her mother, and at a young 99.
The Russian report was based on biographies, interviews and photos of Jeanne Calment, witness testimony, and public records of the city of Arles where she lived.
Meeting Van Gogh
The new article insists Calment's identity “has not been usurped”, according to a statement from the French research institute INSERM, where Robine works as research director.
The authors cross-checked the original data used to validate the centenarian's identity with newly uncovered documents, to show “there was neither tax fraud nor falsification of Jeanne Calment's identity” the article says.
The team also turned to mathematical modelling to counter arguments that her considerable age was impossible.
In every 10 million centenarians, one can reach the age of 123, they said, “a probability that is certainly small, but that is far from making Ms Calment a statistical impossibility.”
“All the documents uncovered contradict the Russian thesis,” Robine told AFP, as the team demanded a retraction from Zak and Novoselov.
Novoselov, however, insisted Monday that the original work verifying Calment's identity and age “is full of flaws and mistakes”, while Zak said he found the new article “weak”.
Born on February 21, Calment became the biggest attraction of the southern French city of Arles since Vincent Van Gogh, who spent a year there in 1888.
She said she had met the artist when he came to her uncle's store to buy paints, and remembered him as “ugly as sin” and having an “awful character”.
Calment used to talk of enjoying chocolate and port and would smoke an occasional cigarette before her health deteriorated.
INSERM said however that it could not “support any requests for exhumation” of Calment's body, on which no autopsy was performed after her death.