Sherlock Holmes and Dr Watson of BBC's "Sherlock" are not returning this year again, or next year, Mark Gattis, co-writer of "Sherlock," has confirmed that "Sherlock" Season 4 is unlikely to premiere before 2016, as it takes a lot of time to write the three 90-min episodes and get everyone together to begin production.

Gattis confirmed the two-year waiting period while answering fans' questions in Brazil. "Writing three films is quite a lot of work and then getting everyone together... [it's] increasingly difficult to get everyone's diaries to align, so we couldn't really do more than three every couple of years I'm afraid," he said, as quoted by Mirror.

The "Sherlock" team would like to reduce the waiting period for fans, but it takes almost two years for everything to fall in place. "By the time we've finished and then everyone starts gearing up again, it roughly takes that long," Gattis said.

The co-writer also revealed that the original plan was for 60 minute episode. He also said that each season was supposed to consist of six episodes. "We ended up doing 90 minute episodes by accident," Gattis said, adding that if they had stuck to the original plan, "everything would be very different."

Meanwhile, Martin Freeman recently made the fans jump in joy by saying that a special episode of "Sherlock" is being considered. "Mark Gatiss may beat me up, but there is an idea for this one-off special that's such a good idea, the actor said on Alan Carr's Channel 4 chat show, as quoted by Huffington Post. He called it a "mouth-watering idea." However, he has no idea when they will start shooting it.

Freeman had also indicated in one of his previous interviews that the original plan was to begin production of "Sherlock" Season 4 this year in autumn. However, the plan had to be scrapped because of actors and creators' busy schedules.

Freeman is currently starring in FX Network's new anthology series "Fargo."