Ryan Reynolds tried to smuggle sleeping tablets into Spain when filming his new movie.

The actor suffered from insomnia as he shot 'Buried' - in which he plays a US contractor in Iraq who is buried alive in a coffin with just a mobile phone and a lighter - so got his family In America to send over some medication but he never received anything because Spanish immigration officials blocked it.

He said: "I'd go home and I'd pace until sun up, like a vampire, and then climb into a coffin to film. I was losing my mind, I hadn't slept in days, weeks.

"In Spain, you can't get over-the-counter sleep aides. Melatonin is a herbal one that I like to use because it's not really harmful. You can't get it there, it's basically like crack.

"I had my family ship it over from America, and it never got to me each time. I tried six times to get it there."

As well as sleep deprivation, Ryan also admitted to suffering from panic attacks while filming the movie.

He said: "Claustrophobic is a primal fear that exists within everybody.

"For me I was enclosed in there and had moments of utter panic that were soothed in various ways. One woman was playing all the roles when we were shooting.

"I had a microphone close to my chest and she could hear my panic attack starting 'cause she could hear my heart accelerating. There were times when I couldn't get out of the coffin with any ease so I just had to stay in there with 50-60 pounds of wood on your chest pressing down so you start to have moments of panic."