Sherlock star Andrew Scott has revealed that the cast of the BBC One show Sherlock have been banned from sharing plot details with family and friends.

The Dublin actor, who plays the legendary detective's arch-enemy Moriarty, explained that producers are taking extra precautions to keep storylines a surprise for fans.

"If I told you what happens they would kill me. I never guessed how the last episode would end. It even surprised me," Scott told the Sunday Mirror.

"It has been fantastic filming the new series but we have all been banned from telling our families or friends what is in the scripts. We are not allowed to speak to anyone."

He added: "I don't think everyone thought it would be so successful. I can see it still on TV in 20 years as we all started working on it very young."

The third season of Sherlock is expected to be screened on BBC One in the autumn.