Feeds
Rex Features
During a 2006 interview, which has surfaced on the internet, the actress said: "I think we're lied to about a lot of things.
"We see other towers of the same kind being hit by planes, are they burned?" she added. "There was a tower, I believe it was in Spain, which burned for 24 hours.
"It never collapsed. None of these towers collapsed. And there [in New York], in a few minutes, the whole thing collapsed."
Cotillard claimed the World Trade Centre's Twin Towers were a "money sucker" and would have cost the US government more money to refurbish than destroy.
The 32-year-old also contested the 1969 moon landings, saying: "Did a man really walk on the moon?
"I saw plenty of documentaries on it and I really wondered. In any case I don't believe all they tell me."
Cotillard picked up the Best Actress Oscar for her role as French singer Édith Piaf in La Vie en Rose.
