Sherlock season 4: Mark Gatiss confirms drama will return as series not one-off special

The actor added production team was close to agreeing dates to start filming

Sherlock's Mark Gatiss as Mycroft Holmes (BBC)

Mark Gatiss has dismissed rumours that the next instalment of Sherlock will be a one-off special, after Martin Freeman implied the show could return for a single film.

Speaking at the TV Baftas, Gatiss said that a fourth series was still “the plan”, adding that the production team were moving closer to agreeing dates for filming the forthcoming season.

“There was talk [of a single film, but] amongst people who have nothing do with Sherlock, I’m afraid,” he told RadioTimes.com.

Creator Steven Moffat confirmed earlier this year that Sherlock will return for a fourth and maybe even a fifth series, adding that he and Gatiss had started plotting future storylines.

He said in January: “Rather excitingly, Mark and I, for no particular reason, just started plotting out what we could do in the future. We plotted out the whole of series four and five. The ideas we had that day, I thought were the best we’ve ever had.”

Production dates for the fourth series are said to be difficult to confirm due to Benedict Cumberbatch and Martin Freeman's busy acting schedules.

Freeman has confirmed to star on the London stage as Richard III this autumn, while Cumberbatch is due to star in forthcoming biopic Flying Horse, about pioneering photographer Eadweard Muybridge.