The man, Jean-Marie Loret, claimed to be the Fuhrer's son in 1981, when he published an autobiography called "Your Father's Name Was Hitler." He died four years later aged 67, not being able to prove his family line.
But Loret's Paris lawyer, François Gibault, told the French magazine that a number of photographs and documents can now support the claim.
He also revealed how Loret got to know about his parentage.
Born in March, 1918, Loret grew up knowing nothing about his father. His mother, Charlotte Lobjoie, had given him away for adoption to a family called Loret.
Then, in the early 1950s, just before her death, Miss Lobjoie told her son that at 16 she had a brief affair with Hitler. He was conceived after a "tipsy" evening in June 1917.
Proof That Hitler Had An Illegitimate Son?