The prisoner Khalid bin Mustafa was captured in December 2001 in Pakistan and is being held in France while investigators probe suspicions that he was involved with terrorism.
French judges have turned down appeals from his lawyers that he be released while he is investigated.
"I was the victim of an immense injustice that is continuing today in another form. But what bothers me is that it is my country, France, that is committing this injustice," he told the Le Parisien daily newspaper on Monday.
The arrival in France of Bin Mustafa followed months of discussions between Washington and Paris.
France has ensured the return of its citizens from Guantanamo, but under French law they have been detained until the charges against them are investigated.
Bin Mustafa was indicted and remains imprisoned in the Paris region as part of the French investigation into suspected terrorist networks.
Bin Mustafa said Guantanamo was so cut off from the world that he did not find out about the Asian tsunami until three months later - when he was handed over to France in March.
"Guantanamo was another planet. We were on the moon," he was quoted as saying by Le Parisien.