Translate the following English sentence to French:
"In our last report, published in October 1999, we were already expressing our concern about the provisional nature of Mr Birdal' s release, with good reason, unfortunately."
Dans notre dernier rapport, publié en octobre 1999, nous exprimions déjà notre inquiétude sur le caractère provisoire de la libération de M. Birdal, hélas, à raison.