J.J. Abrams has admitted he shouldn't have kept Benedict Cumberbatch's casting as villain Khan in the Star Trek sequel a secret.

The 47-year-old moviemaker has said that in hindsight, there really was no need to shroud the casting of Khan in such secrecy.

Speaking to MTV, the director, who is currently working on the new Star Wars trilogy, confirmed that he instructed his cast and crew to deny any reports that suggested the 37-year-old British actor had been cast in the film, Star Trek: Into Darkness, as he wanted to keep it a secret until the movie was released.

"The truth is I think it probably would have been smarter just to say upfront, 'This is who it is'. It was only trying to preserve the fun of it, and it might have given more time to acclimate and accept that's what the thing was.

"It was so important to the studio that we not angle this thing for existing fans. If we said it was Khan, it would feel like you've really got to know what Star Trek is about to see this movie.

"That would have been limiting. I can understand their argument to try to keep that quiet, but I do wonder if it would have seemed a little bit less like an attempt at deception if we had just come out with it."

Khan, previously portrayed on screen by Ricardo Montalban, has been a longtime nemesis of the Star Trek crew.