Was The World's Oldest Person A Fraud? Researcher Thinks So

She earned the title of world's oldest person but now one man is questioning whether Jeanne Calment was really a fraud.

In a new paper, Russian mathematician Nikolai Zak makes shocking new claims about Calment, who died in 1997 at the reported age of 122 years and 164 days old, that suggest the woman may have been 23 years younger than she claimed.

Zak hypothesizes that the woman who died in 1997 may not have been Jeanne Calment at all, instead suggesting her daughter Yvonne had assumed her mother's identity decades earlier in an effort to avoid an inheritance tax.

Zak and gerontologist Valery Novoselov studied biographies, interviews, photographs, census records and other documents in the investigation and cited "many inconsistencies" in Calment's story

According to official records, Jeanne Calment's daughter Yvonne died of pleurisy in 1934, but Zak contends that it may have been Jeanne who died that year and that her daughter assumed her identity and continued out her life pretending to be her mother.

"After studying this case as deep as I could, I can state that the liklihood that Jeanne Calment had really set a record of longevity is extremely low," he wrote, before outlining a series of arguments supporting his claim.

For instance, according to Zak, after Yvonne died, Calment reportedly shared an apartment with her son-in-law until he died in 1963 and helped raise the couple's son. In some of the censuses from the time, Zak said the son-in-law was first labeled as "married" before it was corrected to "widower."

He also points to physical differences between a 1930s-era identity card for Jeanne Calment and the physical description of the woman who died in 1997. The identity card lists Calment's eye and hair color as black and her height around 4 feet 11 inches. But, Calment was later described at 114 as having light grey eyes and reportedly was said to have had chestnut brown hair when she was younger. She was also only 3/4 inch shorter than she had been in 1930s, which Zak said doesn't seem to be consistent with the average changes in height for a woman as she ages. He believes she would have been shorter at the time of her death and pointed to photos that show that Yvonne had been taller than her mother.

He also reviewed interviews Calment had given to the media after her notoriety began to grow, and said there were several  times where she appeared to confuse facts about her life.

"Jeanne was reluctant to give detailed answers about her family; she confused her grandmother with Yvonne's grandmother, her husband with her father, et cetera," he wrote. 

According to Zak, Calment even instructed a relative to burn family photographs after she had begun receiving attention for her age.

Novoselov, who helped with the investigation, said he always had "doubts" about the woman's age.

"The state of her muscle system was different from that of her contemporaries. She could sit up without any support. She had no signs of dementia," he said, according to the New York Post.

If, in fact, the woman who died in 1997 was Yvonne Calment, she would've been 99.

The motivation for the identity switch, Zak believes, could have been to avoid an inheritance tax, which he said could have been as high as 35 percent on large assets during the 1930s.

He also said Calment initially shied away from any attention about her age until after she surpassed the age of 110 and then seemed to relish in the attention.

Before Calment earned the distinction as the world's oldest person, her identity was authenticated by a group that included French demographer and gerontologist Jean-Marie Robine.

Robine criticized the new claims saying it "never examines the facts in favor of the authenticity of the longevity of Madame Calment," the Post reports.

Robine, who said he never had any doubts about the authenticity about the documents, believes the report "appears to me to be defamatory against her family."

After Calment, the next oldest person in history is American Sarah Knauss, who died in 1999 at the age of 119.

[Photo: Pascal Parrot/Sygma/Sygma via Getty Images]