A special one-off episode of the hit BBC drama Sherlock will be shown in selected cinemas around the world, co-creator Steven Moffat has announced.

Speaking at Comic-Con in San Diego, he told thousands of fans of the TV show the story, set in Victorian England, would also be seen "on the big screen".

The fans, some of whom had queued for hours, were also the first to be shown a short scene from the episode.

Set in a snowy Baker Street, it sees the sleuth arriving home after a case.

"Did you catch a murderer, Holmes?" asks a young child, carrying Sherlock and Dr Watson's suitcases.

"Caught the murderer, still looking for the legs," replies the detective, played by Benedict Cumberbatch.

"I think we'll call it a draw."

The trailer ends with the caption "coming soon... ish". Photo taken from BBC.

The new adventure is set in the same time frame as Sir Arthur Conan Doyle's original stories.

Moffat said one of the challenges in writing the episode was exploring the different role played by Conan Doyle's female characters.

"One of the problems with the original, which we addressed in the modern series, is that, for the most part, the women in the original Sherlock Holmes series don't really speak very much.

"And there isn't a Molly Hooper," he added to much laughter, referring to the morgue registrar played by Louise Brealey. "We'd forgotten that we invented Molly."

He also spoke about the continuing appeal of the character of Sherlock Holmes. Moffat's own theory is that "we're always going to be in love with the idea of a man who understands everything but himself".

The first day of Comic-Con saw British drama took centre stage. Another popular event was a Doctor Who panel which also featured Steven Moffat. The show's head writer appeared alongside Peter Capaldi who plays the Doctor, Jenna Coleman, who plays Clara, and Michelle Gomez, who plays Missy.

The 6,500 fans who filled the convention's Hall H were also the first to see the first trailer for the new series which airs on BBC One in September.

Amongst the biggest cheers were those for Game of Thrones star Maisie Williams's appearance at the end of the footage. She was seen greeting the Doctor with the words 'What took you so long, old man?'

During the hour long panel session, the Dr Who team were again asked about the possibility of a woman being cast as the Time Lord.

Jenna Coleman told the audience: "I'm sure it will happen at some point. It's just about casting the right actor".

And Peter Capaldi was rewarded with applause when he paid tribute to the show's history of over half a century, and the enthusiasm shown by American fans at his first Comic-Con.

"It's just an extraordinary experience, the whole thing. I could tell you that the show was successful overseas, and that it was catching on in America. But I didn't realise it was to this scale. So to come here and find this warmth and affection is absolutely extraordinary.

"But the most amazing thing that happens," he added. "I get the affection for the whole 50 years pointed in my direction."

Comic-Con runs until Sunday, 12 July. Forthcoming sessions include panels on Star Wars: The Force Awakens, Game of Thrones, Quentin Tarantino's The Hateful Eight and Batman vs Superman: Dawn of Justice.