The first appearance of Benedict Cumberbatch in the Sherlock Holmes story will be a small role, but it will be the first time the actor has appeared in a feature film.
Sherlock writer-director Colin Baker said the character will be played by a new actor who has not yet been announced.
“We are delighted that Benedict Cumberbet will be making his first appearance as Sherlock Holmes in our Sherlock Holmes television drama,” Baker said.
“The character of Sherlock Holmes is one that we have been wanting to explore since the very first episode of the show.
He has a unique combination of wit, wit and sarcasm, which we are thrilled to bring to life in the drama.”
Sherlock has already become a global phenomenon, becoming the most watched British series of all time with more than one million viewers tuning in each week.
It has been nominated for a best drama series Oscar and received an Emmy nomination for outstanding writing for a drama.
It was originally made for a record £10.5 million ($15.3 million).