The BBC has promised a special Sherlock surprise at the end of tonight's repeat of the season two finale.

The episode is airing at 8.30pm on BBC One and, in a statement, the British broadcaster said: "Don't miss the repeat of 'The Reichenbach Fall' tonight at 8.30pm on BBC One. Our advice - keep watching to the very end!"

Sherlock's third season is currently shooting and features The Killing star Lars Mikkelsen as Sherlock Holmes' latest nemesis Charles Augustus Magnussen.

Sherlock is expected to return to BBC One in late 2013 or early 2014.