HARRY Potter star Emma Watson was taken ill while filming for upcoming 2014 film Noah after drinking stagnant water.

The actor, who went to Dragon School, Oxford is reported to have said she was left “tired and delirious” from dehydration after director Darren Aronofsky forbid water bottles on the set of the biblical epic.

Watson told Wonderland magazine: "Because the film has a pro-environment message, Darren didn't want anyone drinking from plastic water bottles on set.

”At five in the morning, when you're exhausted and delirious, [that] wasn't ideal.

“I was so tired one morning I picked up a mug from my trailer and drank some stagnant water that had been there for the duration – so three months. I was so ill."

Watson had been filming in New York, with Ray Winstone and Russell Crowe.