Benedict Cumberbatch has revealed how his co-stars played a prank which left him filming the new Star Trek movie with his face covered in blobs of sun cream.
Co-star Chris Pine - who plays James T Kirk in the movie - convinced him that they were filming in a high-tech laboratory and needed to wear a protective layer.
Cumberbatch laughed off the gag as the pair appeared as guests on tonight's edition of The Graham Norton Show.
He appears as villain John Harrison in the new film Star Trek Into Darkness, which was given its UK premiere last night.
Speaking about the prank, he said: "We were in a really futuristic laboratory with lasers that were trying to split a target smaller than a human hair to create a continual form of energy.
"And I was like 'wow, this is the real deal - what can't we touch? What's safe?'.
"I got on set and was told I needed to wear 'neutron cream' to protect me. I was gullible and did what I was told, it's America and there is a lot of health and safety.
Pine explained: "We told him he had to apply the cream in dots all over his face and there he was doing this really intense scene with sunscreen spots all over him.
Cumberbatch added: "I should have known. They had me, completely had me. It was really very funny."
The interview is to broadcast at 10.35pm on BBC1.