Sherlock season 4: First photo of Benedict Cumberbatch released as creator warns series could be the last

Steven Moffatt believes the next run of episodes could be the detective's swansong

Cumberbatch will be back for another series of the BBC detective drama, expected early next year (BBC)

Fresh from receiving six Emmy nominations for its Christmas special The Abominable Bride, the BBC has released a first look image from the long-awaited upcoming series of Sherlock.

The image shows Benedict Cumberbatch in character as the eponymous detective - however, in place of his partner John Watson (Martin Freeman) is an altogether furrier friend.

Nobody knows when exactly the new run of episodes will debut, but reports have suggested with "near certainty" that the series will bow on New Year's Day.

One fact that does seem probable is that series four could well be Sherlock's final outing with Moffat telling The Telegraph: “I don’t know how long we can keep it going."

“We do have two film stars in the programme," he added. "They haven’t needed to do these jobs for a very long time; they’re coming back because they want to.

“I would be moderately surprised if this was the last time we ever made this show. But it absolutely could be.”

The modern day drama series, based on characters created by Arthur Conan Doyle, has been a worldwide ratings-puller since its debut back in 2010. Toby Jones was recently announced as the first new cast member to join series four although it is unknown who he'll be playing.