Considering they were looted from the Parthenon in Athens, which is still standing, I would say "yes."
Come on! The Nazis systematically plundered art treasures across Europe. After the war much of that was lost. There is not really much doubt on this.
I really wish you would do some research before spouting off with ill-informed opinions. The Nazis and Italians conquered Greece during WW2, they didn't take Acropolis marbles.
Anyway, Elgin 'rescued' the marbles after a period of particularly egregious destruction of Greek history. Much was lost, blown up or deliberately demolished. If the Greeks didn't give a damn, why should Elgin be blamed for caring?