Hassan Diab's lawyer, Donald Bayne, calls the ruling inexplicable and says he is considering an appeal to the European Court of Human Rights.

French authorities suspected Hassan Diab was involved in the 1980 bombing of a Paris synagogue that killed four people and injured dozens of others, an accusation he has denied.

The French Court of Appeal's decision sparked immediate rebukes from Diab, his lawyer and human-rights groups, as well as fresh calls for Ottawa to launch a public inquiry into Diab's case.