It's been over two years since the last series of Sherlock, with fans treated to just one 90 minute New Year's Day special in the meanwhlie.

So no doubt self-confessed 'Cumberb**hes' will be counting down to until the release of the long-awaited Series 4, which has started shooting in Cardiff.

Leading man Benedict Cumberbatch was spotted back in the detective's familiar navy overcoat as he filmed scenes in South Wales.

He's back! Benedict Cumberbatch was spotted back in the detective's familiar navy overcoat as he filmed the new series of Sherlock in Cardiff

The father-of-one, 39, was spotted sipping on a coffee as he chatted to crewmembers on location in a Cardiff suburb.

Benedict was spotted filming Series 4 for the first time after Sherlock co-creators Steven Moffat and Mark Gatiss confirmed the show was returning earlier this month.

In a statement earlier this month, Steven and Mark said: 'Sherlock series four - here we go again!

The wait is nearly over: It's been over two years since the last series of Sherlock with fans treated to a 90 minute special on New Year's Day

Caffeine fix: The father-of-one, 39, was spotted sipping on a coffee as he chatted to crewmembers on location in a Cardiff suburb

Chic and cheerful! Benedict seemed in good spirits on the scene as he waved at the rest of the crew

'Whatever else we do, wherever we all go, all roads lead back to Baker Street - and it always feels like coming home.

'Ghosts of the past are rising in the lives of Sherlock Holmes and John Watson bringing adventure, romance and terror in their wake.

'This is the story we've been telling from the beginning. A story about to reach its climax.'

Mark has been teasing fans every few days on his Twitter account by posting photos of the back of the castmembers' heads, with Benedict, Martin Freeman and Amanda Abbington included.

Back for more: The actor admitted he was 'thrilled' to be reprising his role as the detective

Benedict, who performed at the live televised Shakespeare tribute in Stratford-upon-Avon, on Saturday night, said he was 'thrilled' to be back as the detective.

He said: 'I can't wait for everyone to see season four. But you will have to wait... though not for long... And it will be worth it.'

Series four will return to BBC later this year with three feature length episodes.

Ready for action: The show's co-creator Mark Gatiss was spotted chatting to crewmembers

Crime caper: In typical Sherlock style it appears there will be a murder to solve as actors were seen milling around the set in full forensic jumpsuit that typically appear at crime scenes

Bobbies on the beat: No 'crime scene' would be complete without a set of policeman walking around, which were perfectly played by a couple of enthusiastic actors

Getting comfy: One extra appeared to be wearing their pajamas on set as they warmed up on the set

Rivers of blood: One crew member was seen walking around the set with a jug of fake blood, suggesting the scene being filmed would be of a gory and graphic nature