Emma Watson had little idea that Daniel Radcliffe had become too reliant on alcohol.
Daniel recently revealed that he had not touched a drop since August last year, when he realised that he was not suited to the party lifestyle.
But his Harry Potter co-star Emma told The David Letterman Show: "To be honest it's really not something that I genuinely know much about. As far as I know he never took a sick day. He was the most professional, amazing, guy" .
Asked about whether she drank, Emma, Hermione Granger in the British films, said: "I have tried spirits - we drink at 18 in the UK, and I am actually legal to drink in the US now too, since I'm 21."
Visibly uncomfortable with the subject, she then exclaimed: "I'm dying here. Can we move on? I don't want to talk about this," while banging her hand on the table.
The actress, who is promoting Harry Potter And The Deathly Hallows - Part 2, admitted: "I got very, very drunk once in my life as everyone does. Fine! I have been drunk - and I shall bow to that".
© Press Association