“The contacts with whom we were working to secure the release of Marie Dedieu have told us of her death,” Foreign Ministry spokesman Bernard Valero said in a statement.
He said Paris could not confirm the date or exact circumstances of her death.
The 66-year-old wheelchair-bound woman, who was recovering from cancer and needed daily medication, was seized in the early hours of October 1 from a private house on the island of Manda on Kenya’s northern coast.
Speaking to reporters after a cabinet meeting, French Foreign Minister Alain Juppe said Paris had been trying to secure her freedom and described her death as barbaric and a case of extreme “brutality”.
“We tried to get her medication through four different channels,” Juppe said. “The kidnappers did not give her the medication, which is evidence of more barbarism.”
Valero demanded her body be handed to authorities.
“France is shocked at the total absence of humanity and the cruelty that the kidnappers have shown with regard to our compatriot, and we want them to be identified and face justice,” Valero said.
Her heartbroken partner, John Lepapa, said news of her death had left him lost for words and his entire family in shock.
“I had been so hopeful that with the swift action taken by the Kenyan government to send its military into Somalia I would see Marie again,” he told Reuters, sobbing.
“The only way to show her respect is for the government of Kenya to repulse the militants and ensure they can never carry out another kidnap from northern Kenya,” he said by telephone from Amboseli in southern Kenya
“She was a sister, a mother and a friend to the people in Lamu. She was the woman I was going to marry.”