"I think we're lied to about a number of things," the Paris-born 32-year-old is seen saying in French.Cotillard's best actress Oscar was one of several awards she won for playing singer Edith Piaf in La Vie en Rose. She is due to begin filming gangster movie Public Enemies with actor Johnny Depp shortly.
In the interview, given to French TV show Paris Premiere, Cotillard appears to suggest the attacks on the World Trade Center were staged to avoid the expense of refurbishing them.
"We see other towers of the same kind being hit by planes, are they burned?" she asks. "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."The Twin Towers, she claims, were a "money sucker" that would have cost much more to modernise than to destroy.
The actress goes on to cast doubt on the Moon landing of 1969. "Did a man really walk on the moon?" she asks. "I saw plenty of documentaries on it and I really wondered. In any case I don't believe all they tell me."