Jean-Michel Andre, 51 said the two messages were sent from Irina Belenkaya's email address on March 21 and 23, but he managed to read them only on Wednesday evening as he rarely uses his email account, the Le Parisien newspaper said.
The first message Belenkaya is said to have written consists of only swear words for her ex-husband. In the second letter, she informs Andre that she is back in Russia and attaches the email he wrote to her last September when he kidnapped Elise in Moscow and returned to France.
While the woman's friends say she would not have sent the messages if she were not in Russia, investigators believe they could have been sent by one of Belenkaya's friends or relatives in an attempt to throw them off the scent.
The estranged couple has been embroiled in a "tug-of-war" for custody of their daughter for two years, with Russian and French courts siding with their nationals in the dispute.
Andre was awarded custody by French courts following the couple's divorce in 2007. After his wife left the country taking her daughter with her, a warrant for her arrest was issued by a French court in 2008.
Belenkaya was subsequently awarded custody of Elise by a Russian court in 2008.
Andre hired private detectives to trace his wife and child. He learnt Russian and traveled to Moscow to secretly take his daughter back to France. Following the kidnapping, a Russian court issued a warrant for Andre's arrest.
Elise was snatched from her father in Arles, in southern France, on March 20 by three unknown attackers, one of whom Andre believed to be his former wife. He was severely beaten in the attack.
Belenkaya was subsequently charged with arranging an attack on her ex-husband to abduct her daughter, and is currently on an Interpol wanted list. If arrested outside Russia, Belenkaya could face up to three years in prison. However, under Russian law, the woman cannot be extradited.
