Emmanuel Macron and his wife, Brigitte, are planning to present photographic and scientific evidence to a US court to prove Mrs Macron is a woman, reports BBC News.
Their lawyer says the French president and Mrs Macron will present the documentation in a defamation suit they have taken against the right-wing influencer Candace Owens after she promoted her belief that Brigitte Macron was born male.
Ms Owens' lawyers have responded with a motion to dismiss the claim.
Speaking to the BBC's Fame Under Fire podcast, the Macrons' lawyer in the case, Tom Clare, said Mrs Macron had found the claims "incredibly upsetting" and they were a "distraction" to the French president.
"I don't want to suggest that it somehow has thrown him off his game. But just like anybody who is juggling a career and a family life as well, when your family is under attack, it wears on you. And he's not immune from that because he's the president of a country," he said.
Mr Clare said there would be "expert testimony that will come out that will be scientific in nature" and while he would not reveal, at this stage, its exact nature, he said the couple were prepared to demonstrate fully "both generically and specifically" that the allegations are false.
"It is incredibly upsetting to think that you have to go and subject yourself, to put this type of proof forward," he said.
"It is a process that she will have to subject herself to in a very public way. But she's willing to do it. She is firmly resolved to do what it takes to set the record straight.
Read more of this report from BBC News.