Carla Bruni-Sarkozy, France's first lady, has vowed to help a grieving Italian mother find out what happened to her son, who died in mysterious circumstances while held in a French prison.
In her letter Mrs Bruni-Sarkozy, who sees herself as a champion for human rights, she said: "I was very deeply moved by your letter and I want to express my deep condolences. I want you to know that I am close to you in your pain.
"I have full faith in the French justice system and they will answer you and the Italian authorities. There is ongoing contact between them both. Be assured you have my solidarity, keep strong and brave. Carla Bruni-Sarkozy."
Mrs Antignano had written to her last month asking her for help after official requests for information from Franco Frattini, Italy's Foreign Minister, to French authorities also went answered.
Mrs Antignano, who had been planning to travel to Paris to take her protest to the French personally, said: "I couldn't believe it when I got the reply from her. I hope as well that my faith in French justice will return."
She added that Mrs Bruni-Sarkozy's reply meant she would be unlikely now to travel to France for a while as the letter had "brought the matter to public attention".
French authorities are investigating the death which took place in Grasse prison and have promised to return the missing organs by the end of next month so that an autopsy on them can be carried out in Italy.
They are also trying to trace a diary he kept in which his mother says he detailed his mistreatment and poor conditions and which has gone missing since his death.
It is not the first time that Mrs Bruni-Sarkozy has intervened personally in cases of alleged injustice – three months ago she attacked Iran's plan to stone a woman to death and was labelled a "prostitute".
Again using a letter she had expressed her support for Sakineh Mohammadi Ashtiani, 43, who was accused of cheating on her husband and then helping to kill him.