Sherlock fans have set Twitter ablaze after catching the first glimpse of Irish actor Andrew Scott in the new Bond trailer.

Scott, known for his role as Sherlock's nemesis, Moriarty, is a villain in the upcoming movie.

His Spectre character is Max Denbigh, cited as the new head of the Centre for National Security.

According to a short synopsis of the plot, he "questions Bond's actions and challenges the relevance of MI6".

The new trailer footage shows two short glimpses of him - one in a fight scene with Ralph Fiennes' character, M, and the other of him starting menacingly at the screen.

Scott referenced his Spectre role earlier in July, in a recorded message for Sherlock fans at Comic-Con in San Diego.

Explaining why he could not attend the convention, he help up a piece of paper that read Spekter 007 Script (Top Secret).

He mentions he is doing "this little film" which is why he cannot be at Comic-Con.

Fan reactions on Twitter to his Bond debut ranged from "Oh my goodness" to a fan called Amy who wrote "No but seriously, look at him".

"Even just the quick flash of evil looking Andrew Scott is enough for me! #Spectre," tweeted Kelly Alyse.

Spectre will be released in UK cinemas on October 26.